My pov is from an hvac tech (n. California) who spends an ungodly amount of time in attics, foam HAS to be installed correctly or its an expensive mess but when done well, it will keep the attics in my area below 100° in the hottest days of summer. Uninsulated roofs without proper ventilation can exceed 150°+ and makes it impossible to safely service hvac equipment for most hours during the day. Love to help you, not willing to die for you
Sorry to hear u live in California but can u tell ppl stay there and not move to other states with the same ideas that messed it up in California. Only thing they are progressive about it leading in stripping rights they didn't know they needed until its to late
I second this, I'm a telecom technician that occasionally needs to get to get to an IDF placed in an attic space. On at least one memorable job I could only stay up there for 10 minutes at a time with long breaks in between to cool down and drink more water. The insulated attics at the same site, just a building away, on an even warmer day, were fairly comfortable.
I do welding and fabrication. Frequently have to get parts powder coated and I’m in there all the time in the summer to pick up parts. Those Mexicans are working in literal 140 degree heat all day long and don’t drink water and maybe eat a few Doritos. So it depends on the individual. If you can’t handle the heat, get out of the… attic.
@@SeamlessFab being cooked alive takes a terrible toll on your health which manifests later on. Ive known a couple techs and installers who arent with us anymore because some dispatcher or service manager didnt care about sending people into that environment
Henry makes a 1” foam sheathing with a silver colored reflective layer on one side. Would nailing it up to the underside of the rafters be a viable option to keep the attic temps down?
I am just waiting for the commercials on tv for “if your home was insulated using spray foam insulation you may be entitled to financial compensation.”
Why should i use spray foam for insulation? Its hazardous in more than one way and burns like dry tinder, when its on fire. I choose rockwool as an insulator, much better for the environment than sprayfoam
@@firstlast8869Even one drop of water can scroll meters in a narrow gap between the wood of the roof and the sprayfoam. It can result in loosen up the whole sprayfoam. Think about a drop of water between two plates of glass.
@@firstlast8869 The foam is mostly open celled and is basically a sponge specify closed cell of better yet install styrofoam vents prior to spraying a closed cell foam.
I thought I might like to have spray foam put into my basement because the fiberglass insulation keeps falling when those little wires pop out. But the thing is, I thought it would be much harder to do any type of plumbing or wiring repairs or upgrades if that stuff is completely encasing the space between the floor joists.
In the UK if you spray foam your roof space and conceal your rafters you will have serious difficulty obtaining or renewing your mortgage. This has to do with concealing rafters and subsequent issues arising from that.
STOP WASTING MONEY ON SPRAY FOAM. You can put in sheets cheaper and they are better. You can leave pockets between them and the roof creating another insulation or allow air flow. You can also get them with radiant or vapor barrier or both one on each side.
This is one of the oddities about some new improved product that's gonna save the world .Many have drawbacks when paired with other products . Some applications are worse than had you just used the Old Way
I saw a comparison of the flammability of silver back, spray foam, rockwool and paper backed fiberglass insulations. The spray foam is HIGHLY flammable. The silver backed took longer to ignite, but did burn. The rockwool had scorch marks where the torch was applied. That’s all. The paper backed fiberglass burned up the paper fairly fast but no fire damage to the fiberglass.
This. Just make sure to have some amount of insulation for during winter in colder climates. Otherwise, a fan exhaust setup with some dampers will do the job just fine for during the summer.
Attitude to spray foam seems to vary wildly, but in UK it is becoming a bit of an issue for some, particularly if installed incorrectly or inappropriately as: - spray foam is relatively expensive due to specialist installation. - it is associated with condensation and premature timber decay. - it can cause loading issues on timbers, especially if retaining water/ timbers have decayed. - retrospective installation might impact on the original design for heating and ventilation, so other modifications maybe required, e.g. due to the change from cold roof to warm roof. - it prevents easy inspection of timbers, so a roof can become structurally unsound before issues are picked up. - depending on the foam used it may not be fire retardant and fail to meet building regulations. - due to low level of fire retardancy and combustible nature of base material, can increase damage caused by fire or accelerate spread to adjacent properties. - it is costly/ difficult to remove. - it can void some building insurance. - depending on building/ installation, it may be difficult to find a lender willing to lend for home purchase. - requires appropriate planning permission on listed properties. - can have a negative impact on home value due to the above.
Insulate ceilings or the attic floor won’t do a thing I lived decades in that house. Freezing upstairs as all heat went into floored attic. Insulated attic ceiling/roof and voila (It was built in 48 before oil inflation was a thing) We wanted attic warmer but cheaper heat bill would have been to have insulated the ceiling on the second floor. Now the attic is ready to finish out tho for a 3rd floor of 2 beds n a bath (if put in new back raised roof)
Unless it’s a vintage home. Then DO NOT insulate the walls. Historic homes are built to breathe -and the VAST majority of heat is lost straight up, through the floors and ceiling. Insulate those.
One thing I did not see in the video section where the spray foam was being applied was the foam vent board that is supposed to be stapled to the bottom of the sheeting to allow the hot air to move from lower section, up to the top ridge vents.
Yes, I can only imagine a lifetime of problems if they are spraying foam directly to the back of the roof sheathing. Sheathing delamination is just one.
Radiant barriers don't stop the sun's radiation. They stop the ceiling from radiating downward into the room. Reflective surfaces are bad at emitting energy for the same reason they're bad at absorbing it. You need the air gap because if anything touches it, the heat simply conducts through it (it's metal) and then radiates into the room from that surface. That's why it has to be kept clean.
Radiant barriers on sheathing do nothing. There has to be an air gap between the radiant barrier and sheathing, but no one wants to deal with the rolls so they just put it on the sheathing to make people think they have a radiant barrier, the don't.
Good luck trying to keep your attic ceiling spotlessly clean! If I had squatters or bums living in peoples houses nearby. I'd do the foam with it to keep the bums toasty warm in the summer.
@@bobbygetsbanned6049yeap. The other way to install it is the reverse with radiant barrier on the outside and an airspace between it and the exterior roofing mounted on furrings
As a UK estate agent of 24 years, please DO NOT install spray foam. You will not be able to sell it to anyone needing a mortgage. It is very expensive to have removed.
This isn’t an issue in the states. Especially here in Texas. Spray foam is actually sought after because it’s so good at keeping the AC in. Summers here are pretty brutal without it.
@@alli3219 they make fire retardant spray foam but it is more expensive, IMHO it should and likely will in the future be required in most installations. They also make a paint like thermal and flame barrier that can be sprayed over existing foam.
I built my house with rockwool batts. Definitely the best decision i ever made in my life. The only reason my house warms up in full summer sun is the windows. And holds in heat during the winter so well i could go naked during an arctic blast. Not to mention how quiet my house is. Sometimes i dont know its raining and hardly wake up from thunderstorms.
Get to know r-value. I'm not disagreeing with you, just that there are huge differences between insulation options and many people just think of it as interchangeable. I have used most every type in different applications. And have had to live with those choices, and what I wish I had done instead. No matter what you do, just understand that you probably need to double or triple the amount of insulation you use between the livable space and the non livable space. Actually, if I had the money and time to do whatever I wanted, I would mount reflective foil backed Styrofoam sheets on the facing edge of the roof trusses creating an air gap. I would either have the reflective foil facing the house and blow insulation in there, making sure to avoid allowing that to fall all the way to the soffits so it wouldn't block airflow. Or, I would have it face the roof and leave the gap without any insulation (so it would reflect back out) and include extra roof vents at the top to create a chimney effect removing the heat from the attic. Obviously you would still need your regular vents to remain unobstructed. All that providing I didn't just seal the whole stock up and treat it like a liveable space.
I removed all the nasty blown in dirty fluff insulation, now im putting Scrim/foil to line the troughs, then im using bats of rock wool, then radiant barrier to enclose it and serve as a floor or allow for some storage,, also i took out all flex duct and bow have sheet metal ductwork, Also rewiring and making the whole space more proper and issue free.
I'm in Canada, radiant barrier is joke here. Foam or traditional bats, but not aginst sheeting. Condensation will rot you out in few years. Always leave an air gap between the sheeting and insulation.
Properly installed spray foam has a special corrugated foam installed next to the roof decking so that the heat and moisture can be vented from the underside of the panels.
In Texas, the scorching sun and high air temperatures lead to high cooling costs. A radiant barrier *can* be a cost effective way to reduce cooling costs. Just don't confuse it with actual insulation, and make sure it is used properly. The radiant barrier uses are limited. It is only useful when placed facing an exterior wall or roof. By reflecting the radiant energy emitted by the wall or roof back to the wall or roof, it increases the temperature of the wall or roof, so you have to be sure the exterior material can handle the heat. Asphalt can melt at those temperatures. If you don't have vented space between the radiant barrier and the exterior, then the heat is trapped, and a large portion of the heat will radiate or conduct to the house, losing a great deal of the radiant barrier's effect. Shiny side facing the exterior with a gap. With a steel frame and exterior, we use a radiant barrier facing our R panel. The panels allow it to vent, and the panel can take the heat. We have bat insulation behind the barrier in the walls. On the roof, the barrier is hung under the panels, and we have blow in on the ceiling. On a sunny summer day, our roof might melt your shoes, but our attic is a good 25F cooler than an attic with no barrier. All in all, the radiant barrier is an inexpensive addition that can make a major improvement to summer performance if it's used properly. As for spray foam.... I can see how it can be useful, but can't see any place where it is either the best choice or the most cost effective choice a a major components in insulation. What a train wreck if it ever leaked from a deteriorated gasket or hail damage! And god help you if you ever have to replace a roof or wall panel! There are cheaper, more manageable ways to get insulation that is just as good. And I would *never* put spray foam on wood. It may be excellent insulation, but it is also a disaster waiting to happen.
Question for you if you don't mind. I'm in Texas also. By shiny side facing out with a gap do you mean to indicate that it's backwards as shown in this video? The reason I'm asking is because mine is done as shown in the video but I can see the actual foam core backing being a gap. Damn straight my roof could probably melt rubber sole shoes this time of year too.
@@Zarathustran In cooler climates, they put the reflective face toward the interior so it reflects radiant energy back at the house. Double sided barriers - like bubble wrap - is also a thing. Think about how it works - all objects warmer than 0 kelvin emit electromagnetic waves. The Sun and heat lamps are well known for this, but it's true of all objects, which is how thermal cameras work. Radiant barriers are very different from normal insulation - the materials used are often conductive to heat. Normal insulation will absorb radiant energy and warm up, but conducts only a small portion of the heat that reaches one face to the other face. A radiant barrier often has an insulation backing or center because the barrier is not 100% reflective - so the foil absorbs some of the energy. The insulating backing reduces the heat conducted from the foil to the other side of the barrier. The reason your roof is so hot is because it is absorbing the Sun's radiant energy. The roof, in turn emits electromagnetic waves (radiant heat) both away from the house and into the attic. If the electromagnetic energy emitted by your scorching hot roof hits foam instead of foil, then your radiant barrier is doing nothing to keep your house cool that regular insulation would not. In a correct installation, the radiant barrier reflects the energy back at the heat source (the roof down south - the house up north), which then absorbs the energy and becomes even warmer. With an air gap, the heat source heats the air via conduction, and the hot air escapes the building. Or, in a northern install, the hot air doesn't escape the building. Something to keep in mind: without an air gap, it's not a radiant barrier, it's a heat conductive non-insulator. aka waste of money. In this video, it looks like foam board with a radiant barrier. Lots of foam board comes with one side foil faced, these days, so that may just be what they had on hand, and they were not actually intending to use the radiant barrier. It also looks like the board is pushed up against the plywood roof. If the foil side is pushed against the roof, then it would not serve any function, so they may as well make it face the attic and have some use in the winter (until it gets foam coated). Is that the case in your installation? Or maybe a yankee installed your barrier? Or - maybe you have bubble wrap (two sided)? With steel construction, my home is very different from what is pictured here. The radiant barrier for my roof is not a face on foam board. They used Solar Guard hung between the purlins. This creates pockets of air trapped against the roof. Because of the ribs in our R panel roof, air caught in the solar guard can flow past the purlins from the eaves to the ridge vent.
There's nothing wrong with spray foam IF it is applied properly and the roof is properly constructed. I wouldn't retrofit it. Go watch some Matt Risinger videos on the subject.
I will never get a house that has spray foam. It can hold water like a sponge, its not fire resistant and is highly toxic when burned. It makes remodeling a nightmare. If you want to spend the money, get rockwool instead.
Radiant barriers are often misunderstood and misapplied. A Radiant Barrier such as Metalized mylar when placed with the reflective surface facing towards the roof will reflect a large amount of the radiant energy that has entered the space and having a very low emissivity will retain a very small percentage of the radiant energy. This combined with an air gap creates a very efficient system.
Unfortunately, you also misunderstand how radiant barriers work. The don't reflect radiant energy back through the roof, they simply are inefficient emitters of infra-red radiant energy into the attic, thus reducing heat flow into the attic.
If spary every inch... 1% chace. The wind still blows when the windows are blew out from the heat of the fire... I got it, i want you to light your couch on fire. Then I want to see you saving your house with foam sprayed on the underside of the roof decking... where you say there no air as you blocked it all.... blahahaha!
In this scenario, the air gap needs to be between the radiant barrier and the roof sheathing if the goal is to radiate heat back outward. The air gap doesn’t have to be much, .75 in. That said, even without an air gap the radiant barrier is still going to work, just not as well. Here in the north, we install radiant barrier on the interior walls to reflect heat back inwards during the winter. It works great.
Rad barrier should be applied on bottom of rafters thus trapping 6 to 8 inches of air that can be drafted out of attic with thw heat radiated down from the shingles. Foam isn't cheap AND if done incorrectly can cause humidity problems. Be sure to have a heat load done by a professional so that the a/c can be sized correctly and the humidity can be addressed before it becomes problematic
Put the ductwork in the insulated knee walls of the attic and avoid conditioning the entire unused space up there. Or put ducts and equipment in the crawlspace. Slabs are cheap and not good for installation of plumbing and electrical
My house in AZ has radiant barrier on top of the roof sheathing, metal frame windows with a reflective metal tint, foil backed glass batts in the walls, nearly a Faraday cage. Keeps out the heat, and cell signals. Phoenix Fire switched from UHF to VHF radios to be able to communicate.
(dons tinfoil hat) SOLD. You can still get a cell signal inside your home using a booster that mounts outside. But you have more control with what signal you're getting so a lot of noise is reduced for wifi and its harder for those outside your home to tap into your network.
Im a big fan of radiant barrier... In florida! I bought a sheet roll of it that has holes for ventilation. All you do is staple it to the rafters. No plans to do spray foam though. I think i spent maybe 400 bucks in foil to do a 2400 sf house. Its a great product but it NEEDS to be used properly. Radiant barrier on the rafters, blow-in cellulose insulation on the floor of the attic
Install furring strips on each side of the truss and then attach polystyrene board (pink foam). You get the foam and an air pocket for the heat to transfer to the ridge vent.
@@N_AUD1 Big Brain probably never had to actually work hands on with it . I suggest install tubing at 1.65 parsecs and connecting it to a geothermal venting system with a low pressure hydraulics using depleted uranium . The objective here is thermodynamic mode of elasticity and molecular transfer of quasi-stellar wind turbines that will effectively increase the R-values proportional to the Newton's 4th law of insulation . Always complicate the simple
@@Sjwolosz321 The guy (@joshwiedenbeck6944) is right though, that's why foamboard with single/double-sided foil is sold. You get the high r-value/inch of foam, as well as the radiant barrier rejecting heat into the cavity under the roof deck. If you use common sense in venting that cavity, you get the best performance/thickness of any common roof system I know of. I'm not a roofer and could be wrong, but I'm pretty sure me & he are right.
I agree with Josh, that radiant barrier most definitely works I built house with both and I crawled around in a house with and without it doing remodeling and fixing a leak caused by the shingles blowing off in a storm and I wanted to check to see all signs of where the water has spread and if I need to do more than fix the shingles and treat the mood and replace drywall. There was a huge difference with no radiant barrier being inside the attic with no radiant barrier. Plus I like using it when sheeting the roof after getting the trusses done because carrying water logged plywood for two or 3 days all day and bending and cutting and the way your back feels so good after words not to mention the extra weight and walking across the trusses with a full sheet of plywood on a windy day, it's feels alot safer when you are gonna carry one or two bunks of plywood by the time your done along with your partners helping out, it's alot easier to not get blown off the roof I feel with the lighter plywood, I can throw it down faster if a fast gust of wind turns up or set it down for a second alot quicker and brace yourself quickly before getting blown and having to back pedal on 1.5 trusses with a 60 to 80 lb kite depending on if it rained the night before or that day. But you definitely need the air gap to ventilate right under the radiant barrier, the gap also allows the heat to not transfer directly into the insulation and heat up the attic, think of a tall tree or tall metal flat roof that u see with solar panels on them that they put in parking lots nowadays, the things are like 20 ft or 25 ft tall. If u put ur head right under the sheet metal it's probably pretty damn hot, but at ur head level of 6ft and ur car height, it's way cooler with that roof that high up even with no insulation or roofing just sheet metal and solar panels, even with out solar panels they provide way cooler car temperatures in ur car if it's parked under it all day in 95 degree weather, it's like 75 degrees under it at head height. But if u use that radiant barrier and insulation correctly and also well placed solar air vents that spin to suck hot air out, you could make a house in 90 weather pleasant with no a/c , just a fan on medium or low if needed and may not need any fan or a/c at night. You could spend an extra 15 grand on radiant barrier and solar vents and insulation done right and ridge vent and make use of any Dutch gable or just gable to put a big solar vent on the end if each vent on each end and on top, if u put 4 solar vents and ridge vent and bird blocks and maybe a couple cheap metal vents on the side hidden from the curb appeal side of the house to not make it look ugly ir cluttered. You could do a science project and build a little flat roof dog house and 3 different versions I bet the farm if u did all three the inside temperature of the dog house done right will be 10 degrees cooler and in a house I bet at least 10-15 degrees cooler with all three in hot climates and times that by 365 and the electricity u save per day with less or no a/c possible no a/c in winter months and just fan use and some a/c to sleep or just 2 or 3 hours a day in summer compared to 8 hours of a/c in all rooms all year almost , You pay for itself in the first year and when u use the a/c u don't feel guilty or feel like money flying out the window which makes the times when u do use the a/c feel so much better and far more effective especially if it's a day off and u feel like a/c and don't care what it costs because it's too hot and u want to enjoy ur Saturday
Closed cell foam does NOT absorb water at all. It there is a leak on the wood roof surface, it may be dificult to locate because it will not show up in the attic as the foam does not let water go thru.
When I see spray foam my first thoughts are trapped moisture in the wood and rot, the moisture would dry out quickly if the wood has room to breath as my house built in 1935.
@@sequoiapietri5473 I have seen this in uninsulated cottages/homes from the 1930's . Unsealed buildings are remarkable for the longevity of unpainted wood, siding, window frames and even asphalt? shingles.
I did radiant barriers for 6 years. How to apply radiant barrier depends on the climate and what you're hoping to achieve. Like you mentioned in your video, without an air gap, radiant barrier on the sheathing can raise the temperature of the attic-increasing your cooling costs and decreasing your heating costs. Most of the time, the more efficient use of radiant barrier is across the "floor" of the attic space. Reduces the heat envelope of the home and essentially reflects heat back down in the winter and out in the summer. Put in some solar fans, and your attic can be within 10 or so degrees of the temperatures outside which is also good for your shingles!
Radiant barrier on top of the rafters. Rockwool (or other sheet types) at the bottom. Add to that heat-reflecting paint on the roof tiles to create a super barrier. Only if you don't have winters.
It doesn't reflect heat away, and it doesn't transfer any heat to the air. It's pretty much the opposite. The purpose of the radiant barrier is to prevent the hot roof sheathing (heated by the hot shingles, which are heated by the sun) from radiating that heat into the attic. It's supposed to keep the attic cooler in the summer, and theoretically introduce less heat into the house and reduce the electricity needed for cooling. The only thing you're correct about is that it needs an air gap in order to work, and that applying spray foam over it makes the radiant barrier useless. But that radiant barrier is pretty much a waste of money in any case.
@@fugu4163Actually most exotic cars will start to appreciate after a certain amount of time. Old air cooled 911s are worth much more now than they ever were new. Countach's are going for $400k minimum now. However your Kia will eventually be worth zero. Seems like you just have a knack for poor financial decisions.
im surprised no one is mentioning that when sprayfoam is applied to the roof sheathing, it will dramatically reduce the lifespan of the roofing underlayment. it drastically increases roof deck temperatures, because it blocks the heat from radiating through. generally its better to double down on insulation above the ceiling than to try and keep the heat out of the attic. if your building cant breath, you will get mold. even in the hottest climates. vented attic spaces are extremely important.
In Australia we call this Sisalation and its stock standard on all houses that have tin (colour bond) roofs. I’m pretty sure it’s regulation to actually have this with a colour bond roof. Either spray foam or bats are usually installed along with this. Generally not used with tiled roofs.
I had a left over roll from a shed installation where it was used on the roof only. Had enough to cover a sun facing wall and it does an excellent job.
Spray foam is nice until your roof is leaking. Spray foam retains the moisture and it is not until it is soaked that a leak will occur. As a roofer, I’ve seen some crazy things. We recently completed a house where the HO had rotted sheathing, when we cut it out and remove it, the truss came up with it. The foam retained all the moisture and eventually deteriorated the truss. Had to get an entire out for the HO and it up costing them thousands of dollars.
In the uk you wont be able to remortgage your house or get a mortgage onna house with spray foam because of that issue. Also it can cause timber to rot
I find it fascinating that in the UK spray foam can invalidate your mortgage and after the government did grants for it at the turn of the century it’s now considered a hot fucking mess to sort out
We have close cell spray foam in our house. It reinforces the structure of the house, so that's why we chose it since we live in tornado alley. Its amazing at dampening sound and insulating. However, we've had roof leaks and it has been an absolute pain to locate the leak source, not to mention the concerns about mold. If i could do it again, I'd make sure we have a way to remove it easily and replace it with sheet foam where needed. Maybe a barrier like this would peel?
It actually won’t last a tornado, category 4-5 tornados are capable of leveling cinder block and masonry construction If you’re not underground, nothing will protect you
@@AvoCattoTV for sure it helps. Search for „BMI Windsogrechner“. You can calculate everything there. If the roof is made well, 180km top speeds are no problem.
If that silver layer is in direct contact with the sheathing, it's installed incorrectly: it does NOTHING for conducted heat (i.e. shingles>sheathing>foil). It MUST have an air gap on BOTH sides, as it reflects RADIANT heat (wow, it's even in the name!). But you need a material transition for it to become radiant heat (i.e. hot solid>air>radiant barrier) to do ANYTHING. I stapled radiant foil on the bottoms of my rafters, leaving air gaps at top & bottom for airflow & cooling for the backside of the sheathing, and you could feel an immediate drop in temps below the barrier.
You need at least 1" gap to make a radiant barrier work. I have a decoupled walls on my 1st floor and laminated silver foil rigid insulation onto the block walls, allowed a 1" gap and then framed walls that are conventionally insulated. This works incredibly well.
The ideal solution is a trifecta: ~ radiant barrier to shed heat from the roof ~ those gussets/channels to provide a 2" deep channel ~ spray foam to insulate the attic from the gussets While the gussets are sometimes used by themselves, they have two key flaws: thermal interaction with the sheathing and no tangible R-value. The radiant barrier addresses the first while the spray foam (mostly) addresses the second.
Biggest problem of spray foam in south Florida is the moisture build up in your attic because spray foam literally seals it up hermetically. I’ve heard horror stories. My HVAC installer who said a customer who sprayed foam was having major issues with the ac ductwork completely drenched from all the condensation build up and ruining all the ceilings in the home. Also a roofer I know said he’s seeing problems with the plywood turning soft from the built up moisture inside it. I have a very large home and what worked excellent for me was insulating the ceiling with blown in highest amount possible and then I installed a commercial kitchen roof exhaust fan on a timer from 10am to 6pm in the summer time. This worked like a charm, we were able to do all the attic electrical and HVAC without breaking a sweat.
We've got a walk in uninsulated attic that I'd love to turn into living space but I don't want to put foam insulation in the rafters. It's a 120 year old house and I'd rather not do something that is impossible to undo.
@@_-0_x_-_p_0-_ Oh, the rafters are straight as an arrow. It's all number one full dimension 2x6's and the best stuff I've ever seen. What it isn't is consistent in spacing. 16", 17 1/4", 15 3/8", and so forth. I've looked at the styrafoam/fiberglass and that's likely how we'll go. I'd like to do a cold roof with the air channels just on the underside of the decking - which is doable as the eaves can be opened to vent into the attic, up the roof, and into the area of the attic above the 7' height where there are already cross braces, and out a ridge vent. But that's too big and complex for me to want to do.
@@_-0_x_-_p_0-_ Oh, I bet, hardly anything is flat, level, or plumb in old houses. I can handle the wonky spacing though it sure makes everything more of a custom hand fit operation. The one that annoys me is the floor joists in the attic, they are consistently on 16 1/4 centers. Someone must have used a spacing stick that was just a little off.
Foam paneling can be removed. It needs to be installed well, and it'll take about 4 inches off the height of your attic's ceiling once installed, but it's held in place with long nails and has tape between the gaps, with a radiant barrier underneath. 4 inches of that insulation should rate approximately R20-R30, depending on what was used. It's pricey to have installed professionally, and it's a pain in the ass to get up into some attics, but it does work.
I've pulled cable through an attic that had been spray foamed in the rafters in Texas during the summer. It made a tremendous difference in the temperature of the attic. Even without the attic being air conditioned, it was cooler than the outside air.
During the summer my Gf ceiling got really warm. So I went up to the attic and notice there wasn't much blown in insulation in the attic. So I added an additional layer of R13 insulation, vented the attic by installing wind turbines to the roof, and ceiling fans in all the upstairs bedrooms. Years ago it cost me about $1000 in material and several days to do. Saved big bucks on not having to run the AC or heater as much and added to the value of the house.
@@rsmith02 True, but I live in So. Cal. so I get the ocean breezes. I don't run the AC very much. I have 3 wind powered turbines on the roof so there is no power usage. Power ventilation in the attic is used only in the evening for a couple of hours when the temps are below 70.
Spray foam is a great place for termites to hide and eat the wood without being seen. I work in pest control and I see termites living behind anything stuck to wood. Maybe it's okay to spray foam the attic but don't do it in a crawl space at all. Get a moisture barrier that comes up the walls 6" and leave the foundation bare so we can see it. It helps to seal the crawl vents and every penetration and install a dehumidifier. That keeps the air dry so bugs don't like it. It also makes your house healthier.
I would never use spray foam. Stuff is a nightmare to remove when shit goes wrong. Your roof deck needs to breathe. Nothing wrong with insulation and soffit vents and a ride vent. If the decking gets wet it can dry out. Spray foam will keep the moisture locked in.
As a framer of nearly 30 years, I always felt the radiant barrier should be installed face up. If you ever stepped on a piece laying on the ground face up, you'd understand it's where all the real work is done.
Take 2 sheets of OSB, one with foil, one without. Place then on the ground in the sun. The foil faced sheet will heat up slower, because the foil reflects a lot of heat. However the foil faces sheet will eventually get hotter because the foil slows down thr rate at which heat re-radiates from the board (emissivity)
Ive never seen that in Germany either, i think its not approved by anybody. And how americans build houses is insane... paper thin walls, no insulation under their floors, no insulation between rooms, single glas Windows
@@CookieMonster-vn6zb Dude you're 100 years late. I'm a European and I live in the US and houses are built super well these days. Yes the walls are framed in wood but they are pretty solid due to the way they are engineered together. Unless you're building a bunker in a tornado area this is appropriate. Most places don't have tornadoes in the US..... As far as insulation and various building components they far exceed Europe at this point. Insulation is super thick, VASTLY more than most existing houses in Europe (on par with new construction in Europe). Windows are triple pane these days. BTW insulating between room doesn't bring energy benefits, only noise insulation IF you need it. Most people don't. Bottom line is you're just another kraut trying to trash non-german things without info.
@CookieMonster-vn6zb where do people get these American stereotypes? Since I started construction 20 years ago, I've never seen a new single pane window installed, our thinnest walls are framed in 2x4 lumber and are about 4 inches thick, we absolutely insulate under floors unless the crawl space or basement is a completely conditioned area and in that case the walls of the conditioned space is insulated, and insulating interior walls does nothing for efficiency and if only good for reducing sound which may people do for that reason but it isn't mandatory.
@CookieMonster-vn6zb double pane windows were literally invented in America. I'm not trying to be offensive, but I believe a lot of the things Europeans make up about America comes from a strange inferiority complex.
Each layer serves its purpose plywood aluminum backing and foam it's a triple layer of heat reduction which in the end in overtime will save you in multiple categories
What I did was bridge the wood heat gap, put radiant foam sheets on the rafters and wood, and then spray foam over the foam. My attic temp in GA is ambient to whatever the house was set to, minus three days. My house sits at 70 degrees. My roof has zero moisture.
The foil was misapplied in the first place. It should not be applied to the bottom of the sheathing. It should be applied to the 2 x 4 or 2 x 6 rafters away from the sheeting in that way, it will reduce the heat and you won’t need any spray foam.
I don't disagree, with a typical roof. But in a flat roof situation, some roofers want a closed cell foam to prevent moisture from getting to the decking. Especially with hot to cold transfer.
@@Black_Dirt_Contractorif it’s a hit roof, spray foam is probably ok, just can’t do it on a cold roof that needs any type of ventilation. I’ve just had to redo my entire roof that had really crap “wool in plastic bags” installed, it’s a cold roof in a home built in the 1800’s, so i’ve had to batton it and use PIR for best insulation, but still providing that breathable airgap. It’s been “fun”… 🤣👍🏼🤣
Radiant heat is what the foil is for. No one pays extra for the foil except the builder only because it's required by code. Foam is for conductive heat. It is not a waste to have both. The issues using foam on your attic is far more troublesome.
Spraying foam on the bottom of the Roof deck is a HoRRible thing. Do not do it. It will ROT the roof deck Off. Its closed cell foam that means "No OSMOSIS".
12:00 not all putty pads are fire pads. In my experience, if it’s red it’s a fire pad, if it’s grey it’s a sound pad only. Fire pads are only necessary for fire walls (in my neck of the woods), and for fire walls you should also be using fire caulk to fill any cracks or holes.
have used radiant barrier AFTER both spray foam (first) in the cavities, topped off with 2 inches of fiberglass, 1x3 slats topped with radiant barrier then another 1x3 run of slatting so there is an air gap between the ceiling material and the radiant barrier - theory is to help radiate the heat back towards the living area (cathedral ceilings)
I’m been in the hvac and building science industry since 1986 and have seen both closed cell spray foam and radiant barrier in action. When it was time for me to reroof my home I opted to go with radiant barrier OSB and wait a few years before installing R44 insulation just so the I could measure the difference. I also have a whole house fan. The radiant barrier dropped was worked out fantastic and my attic doesn’t get above 100 degrees F, in the past it would get as high as 130 F. And heat that is built up during the day gets exhausted in the cool evening with my whole house fan therefore the heat never builds up (stored energy).
I live in Phoenix, Arizona. Plumbing is in the attic. We had an attic temperature of 157 degrees my first summer here. Scalding water that you would have to run for minutes. I looked at both, went with spray foam. It is amazing the difference that it makes. Wouldn't change a thing.
You need to determine what type of attic space/roof system you have. Open or closed attic/roof system. If you have an open attic/roof then the ridge vent and the soffit needs to be installed correctly. The attic needs to have cooler air enter the attic throughout the soffit and exit through the ridge vent. Adding spray foam to an open type of attic/roof is a mistake. The stored heat in the roof will destroy the roof shingles. You will also cause a moisture issue in the attic. A closed system keeps heat out. There is no air movement. That this system you want to heat and cool the attic space with a thermostat set 10-20 degrees higher or lower than the rest of the house. The type of roof will determine which system is best for the house
I own a roofing company and I’m telling you do not spray foam your tresses unless you have baffles in them. The roof sheathing has to have air circulation or you will have problems and it will cost a fortune to replace rotted wood stuck to foam. Not sure if it works the same for walls.
You're _so_ close. Radiant Barrier is used to reflect heat back to the place it's coming from. In order to do that, it needs to have an airgap between it and the direction the heat is _coming from._ Radiant barrier facing the attic keeps heat inside the attic. Radiant barrier on the underside of the rafters reflects the radiant the heat from above the rafters back up, and reflects the heat from below the rafters back down (keeping the attic warmer). So, you're right that sprayfoam on the radiant barrier kills its usefulness, but not _why_ it kills the usefulness.
In practice, materials that are reflective also have low emmisivity. You don't reflect the heat back, you reduce radiant transfer into the attic in the first place. Good try with your reasoning, but you are mistaken. You can point radiant barriers into and out spaces, and the effect is pretty much the same. Heck, radiant barriers in the middle of foam still do a good job of stopping radiant heat transport. Its just that even with insulating materials, conduction is much more efficient than radiation over a short distance.
That radiant barrier doesn't work anyways. The airgap has to be between the sheathing and the barrier, since it's touching the sheathing it does nothing.
@@stevepest4143 Yeah he talked about it, but not correctly. The radiant barrier has to have a gap between it and the sheathing, if it's touching the sheathing it won't work.
Radiant barrier on the back of the roof sheathing is a waste. Like you said you need that gap and that gap would be the rafters. If you're going to use spray foam it should be the closed cell spray foam. You also need baffles to help guide the air from the soffits. I would also put the total equivalent of R60 in the attic, along with air sealing it.
When I was doing construction years ago I thought about a system where the radiant barrier is stapled to the bottom of the rafters and use a ridge vent. Keep the soffit vent open to the space in that radiant barrier and let that air flow in and up the inside of that barrier under the roof. The air travels up to the ridge vent and out taking heat from the roof with it. Then use a standard gable vent or powered vent to ventilate the attic. What do you think of this idea? I even got fancy with my idea and ran water lines in there to be pre heated for the hot water system.
Absolute optimum is as follows: Hot side Air gap Then Radiant barrier (to reflect radiant heat) Then High R insulation (to slow conductive heat) Moisture barrier between hot side and structure (e.g. between roof and rafters in hot climates, or between living space and joists in cold climates) Air barrier somewhere (to block heat convection, i.e. to keep hot air from moving to the cold side and keep cold air from moving to the hot side) N.B. You can have two, alternating hot sides. In that case, you want air gap, radiant, insulation, radiant, air gap
@@grumpy3543 the only difference from place to place is which side is the "hot" side. Heat always moves from hot to cold (on an atomic level, think of it like a "hot" cue ball or bowling ball adding motion to a "cold" rack of balls or pins; the moving ball can change the rack, but the stationary rack does nothing to a ball that is misaimed). Heat has only three ways to move (in order of importance to keeping houses comfortable): --Convection: the hot things moving. That's why fans are so good at keeping you cool: they move the air your body has heated away. Walls mostly block this, but the better sealed the envelope of the building, the better it maintains the temperature. --Conduction: hot things touching one another. That takes time, which is why even entirely metal fire pokers aren't as hot at the handle as at the business end. That's (most of) what insulation blocks. --Radiation: a small amount of heat transfers via (invisible) light. this is why/how IR cameras work and can tell how hot something is: the hotter it is, the more it radiates. The more light something reflects, the less it absorbs to heat it up. The reason you need an air gap to make radiant barrier work is that the only radiation that makes it through is that which doesn't hit something else along the way. There aren't many molecules in air, there are in liquids and solids. This is relevant to radiant barriers in that the radiant heat they reflect can't go anywhere, and just gets conducted back into it. So, yeah, the design I shared works everywhere... so long as you know which side is the "hot" side
Be sure to make sure your spray foam installer is using the right foam. The problems in the UK stem from people who do not know what they are doing installing the wrong product or installing it incorrectly and causing issues that can cause your roof to rot
Radiant Barrier decking was designed to reflect the heat back upward that's why in real hot climates it causes the shingles to buckle. So insulating it with spray foam does not matter
False. The radiant barrier decking simply reduces the amount of heat flow from the already hot roof into the attic by reducing the amount of infrared radiation from the aluminum surface on the inside of the attic.
We’ve had radiant barrier on our roof for the last 25 years and it’s worked excellent and we’re gonna apply it again on another roof. It’s really up to your discretion on what to use, but it does bring down the heat in your attic or now that we turned our attic in loft
Until you have a roof leak that you didn’t know about; and now you have rotting boards from the water sitting between the foam and sheathing for years.
You missed the part where radiant barrier isn't intended to be used by itself, but with fiberglass or mineral wool bat insulation installed a couple inches off the surface of the radiant barrier. There are three modes of heat transfer: Radiation, Conduction, and Convection. The radiant barrier has very low emissivity and is designed to reduce the amount of radiant heat transfer into the building from the sun beating down on the roof. It does not, however, reduce conductive heat transfer (which is what insulation is for), so if you touch it all of that heat will come through to your hand or to any insulation you put up against it. In most cases a properly installed radiant barrier with bat or foam board insulation installed with the necessary air gap will keep the attic cooler than spray foam. It is also far easier to detect leaks and to make roof repairs than when you use spray foam. Also, if you live somewhere that gets cold in the winter and hot in the summer, the expansion and contraction of the wood framing can cause the monolithic rigid spray foam to crack and separate from the wall. Every product has it positives and negatives, but unless your house is in a very specific climate and is designed appropriately for it, I wouldn't use spray foam in the attic, especially on the underside of the roof. It is excellent for below slab insulation and for insulating basement walls when installed correctly, and can also be a great choice for difficult to insulate areas and to help make that air barrier transition from the basement wall to the wood framing. However, it is not the best choice for every place you need insulation, and is more often than not the wrong choice.
Do not use either it's all about the airflow because it's not just about the heat but also the moisture the most important thing is moving the moisture to prevent mold also many shingle manufacturers say if you use spray foam underneath the roof deck it will void your warranty. Spend the money on doing it on the ceiling space Best bang for your buck.
If you have HVAC equipment, you need to insulate the roof to protect the equipment from unnecessary wear from the blistering heat or from leaks when it's below freezing. Think of your attic like a vestibule, if the roof is properly insulated, it won't cost as much to heat/cool the 2nd floor. If you're only insulating the floor of the attic, now your 2nd floor is going to require more energy to heat/cool. Pay monthly bills for the extra energy required or pay for insulation once? Keep in mind that outside the roof it might be 100° but inside the attic it's 150°. You're fighting more extreme temperatures if you're not insulating at the roof. Spray foam or insulation batts? Your call.
@@notjamesiha I don't understand why people use foam when there is wool, that thing breaths and correct use of foil works wonders, esspecially with HVAC stuff... I'm a euro', We use wool extensively on roofs of houses - it keeps the house warm during Winter, cool in the summer. Also great point about costs, that's the only reason I increased My insulation, it decreased the energy requiered for heating by 20kwh on an' average Winter day 😅 + 11kwh on cooling during summer. All with just a foot thick, decent wool, previously there were 4 niches of trashy poorly installed and worn down Glass wool. Return of investment in 5yrs was the theory, energy went up enough, along side instalation and material costs - it will be 2yrs tops. Greetings
WARNING!! my father has problems selling his house after having spray foam in the Attic. apparently the foam rots the wood. I don't know the total ins and outs of it but check first it's compatible with the wood.
Spray foam is 100times better I have it in my attic and the temp in my attic year around is always 10 degrees different from the temp in my home. Spray foam attic is 100% the way to go.
A lot of Mortgage companies are now refusing to mortgage homes that have been spray foamed as they can't inspect the roof structure once it has been covered..
Where I live we don't spray the spray foam up against the sheeting where the shingles are we have our 30 in the ceiling of the house and then the attic space we just leave alone Now if you have an attic space that can be finished then we will insulate up against the sheeting where the shingles are because that's going to be the ceiling of the finished attic space but generally if you have a regular house with a 4/12 or 5/12 pitch roof we just put an r30 in the ceiling of the house and then we put baffles against the sheeting then we will use perforated soffit where the overhang is and that allow air to go up to the ridge vent.
Reflex against the roof sheathing and then over the joist allowing for a barrier to be put in place with a 21R factor. Works just fine and lowered my heat in the attic by 15 degrees, easy to repair and install. Spray foam ha toxins and is harder to replace if damage should happen.
If you plan on living in your attic then insulate the roof rafters. If not just insulate the ceiling joists. Don't use spray foam, it contains formaldehydes. When your roof leaks and it will, good luck with spray foam. Wood will not dry and just rot.
So if sofet vents are installed correctly and insulation is stapled to bottom of roof rafters the air gap is perfect with ridge vent is included this will out perform the rest. If you add gable vents this even make the system work better.
The required air space is between the barrier and the roof, not the barrier and the attic. The barrier is supposed to droop to allow a small airspace between it and the roof boards. Expanding foam will press against the barrier and remove that air space, and that's why you shouldn't foam directly over it.
While I agree the radiant barrier does very little during cooling season, it does lower heat loss during the winter. The problem with radiant barriers is that you have to clean them: dust, which can attach even on the bottom, reduces the reflecting property. Depending on the coating, oxidation can also reduce reflection.
My pov is from an hvac tech (n. California) who spends an ungodly amount of time in attics, foam HAS to be installed correctly or its an expensive mess but when done well, it will keep the attics in my area below 100° in the hottest days of summer. Uninsulated roofs without proper ventilation can exceed 150°+ and makes it impossible to safely service hvac equipment for most hours during the day. Love to help you, not willing to die for you
Sorry to hear u live in California but can u tell ppl stay there and not move to other states with the same ideas that messed it up in California. Only thing they are progressive about it leading in stripping rights they didn't know they needed until its to late
I second this, I'm a telecom technician that occasionally needs to get to get to an IDF placed in an attic space. On at least one memorable job I could only stay up there for 10 minutes at a time with long breaks in between to cool down and drink more water. The insulated attics at the same site, just a building away, on an even warmer day, were fairly comfortable.
I do welding and fabrication. Frequently have to get parts powder coated and I’m in there all the time in the summer to pick up parts.
Those Mexicans are working in literal 140 degree heat all day long and don’t drink water and maybe eat a few Doritos.
So it depends on the individual. If you can’t handle the heat, get out of the… attic.
@@SeamlessFab being cooked alive takes a terrible toll on your health which manifests later on. Ive known a couple techs and installers who arent with us anymore because some dispatcher or service manager didnt care about sending people into that environment
Henry makes a 1” foam sheathing with a silver colored reflective layer on one side. Would nailing it up to the underside of the rafters be a viable option to keep the attic temps down?
I am just waiting for the commercials on tv for “if your home was insulated using spray foam insulation you may be entitled to financial compensation.”
never gonna happen, you won't even be allowed to own property soon enough
In the UK homes are unable to be sold if they have spray foam insulation...
Why?@@christinesmith3092
"Due to fears it damages roof timbers"@@christinesmith3092
There has been cases of Sickhomes...
Caused by Improper mixer or uncured/too much..
I just let the black mold insulate my attic
😂😂😂 I wasn't even ready for a comment like this😂😂😂
And when it spreads enough to become sentient it will thank you by sparing your life.
Bahahahahahahah
Man of classic taste I see
I tried but the meth lab fumes keep killing the mold.
Why should i use spray foam for insulation? Its hazardous in more than one way and burns like dry tinder, when its on fire. I choose rockwool as an insulator, much better for the environment than sprayfoam
Also rockwool doesn't burn! Like at all! Because it's a rock!
@@Attaxalotl it just melts at very high temperatures
@@Kinsanth_ 1100C+, most house fires are only around 600C
@@Attaxalotl both temperatures are insanely hot x3
Spray foam is nice applied like that until you get a roof leak then you’ve got problems.
Why would foam give you problems if your roof is leaking? Does it just make it hard to pinpoint the location or is there something else?
@@firstlast8869Even one drop of water can scroll meters in a narrow gap between the wood of the roof and the sprayfoam. It can result in loosen up the whole sprayfoam. Think about a drop of water between two plates of glass.
@@firstlast8869 The foam is mostly open celled and is basically a sponge specify closed cell of better yet install styrofoam vents prior to spraying a closed cell foam.
I thought I might like to have spray foam put into my basement because the fiberglass insulation keeps falling when those little wires pop out.
But the thing is, I thought it would be much harder to do any type of plumbing or wiring repairs or upgrades if that stuff is completely encasing the space between the floor joists.
Spray foam a new roof
In the UK if you spray foam your roof space and conceal your rafters you will have serious difficulty obtaining or renewing your mortgage. This has to do with concealing rafters and subsequent issues arising from that.
@@1celloheaven as far as I know we don't have that yet in the Republic.. But I understand, I would never buy a house with SF used in it anyway.
@@IzzyZon Wise decision to be sure ! :)
? Renew a mortgage? The bank decides ? Interesting concept.
@@Buzzkill3-ak47 with renewing here you need a surveyor. Once he discovers spray is used, certain banks can refuse renewel!
STOP WASTING MONEY ON SPRAY FOAM. You can put in sheets cheaper and they are better. You can leave pockets between them and the roof creating another insulation or allow air flow. You can also get them with radiant or vapor barrier or both one on each side.
Amen
stop wasting money? lol you need some building science education.
I work in hvac and man ill tell u what sprayfoamed attics were the nicest!! Temperature in the attic dang near felt like the inside of the house
This is one of the oddities about some new improved product that's gonna save the world .Many have drawbacks when paired with other products . Some applications are worse than had you just used the Old Way
The problem with spray foam it hides damage
I saw a comparison of the flammability of silver back, spray foam, rockwool and paper backed fiberglass insulations. The spray foam is HIGHLY flammable. The silver backed took longer to ignite, but did burn. The rockwool had scorch marks where the torch was applied. That’s all. The paper backed fiberglass burned up the paper fairly fast but no fire damage to the fiberglass.
Ventilation is key. Isolate the rest of the house and let the attic space breathe.
This. Just make sure to have some amount of insulation for during winter in colder climates. Otherwise, a fan exhaust setup with some dampers will do the job just fine for during the summer.
Any space I can't use for a room is wasted space. Who the hell needs attic? What is it, 1640?
Not sure why more homes in FL don't have an attic fan.
LP actually says foam insulation over the rad barrier is OK. As long as the ridge vent and eaves vent paths are not Obstructed in any way.
@@randomnickifyRoof pitch creates it regardless.
Attitude to spray foam seems to vary wildly, but in UK it is becoming a bit of an issue for some, particularly if installed incorrectly or inappropriately as:
- spray foam is relatively expensive due to specialist installation.
- it is associated with condensation and premature timber decay.
- it can cause loading issues on timbers, especially if retaining water/ timbers have decayed.
- retrospective installation might impact on the original design for heating and ventilation, so other modifications maybe required, e.g. due to the change from cold roof to warm roof.
- it prevents easy inspection of timbers, so a roof can become structurally unsound before issues are picked up.
- depending on the foam used it may not be fire retardant and fail to meet building regulations.
- due to low level of fire retardancy and combustible nature of base material, can increase damage caused by fire or accelerate spread to adjacent properties.
- it is costly/ difficult to remove.
- it can void some building insurance.
- depending on building/ installation, it may be difficult to find a lender willing to lend for home purchase.
- requires appropriate planning permission on listed properties.
- can have a negative impact on home value due to the above.
Insulate the walls and ceiling of the house. Then floor the attic.
Insulate ceilings or the attic floor won’t do a thing
I lived decades in that house. Freezing upstairs as all heat went into floored attic.
Insulated attic ceiling/roof and voila
(It was built in 48 before oil inflation was a thing)
We wanted attic warmer but cheaper heat bill would have been to have insulated the ceiling on the second floor.
Now the attic is ready to finish out tho for a 3rd floor of 2 beds n a bath (if put in new back raised roof)
Unless it’s a vintage home. Then DO NOT insulate the walls. Historic homes are built to breathe -and the VAST majority of heat is lost straight up, through the floors and ceiling.
Insulate those.
One thing I did not see in the video section where the spray foam was being applied was the foam vent board that is supposed to be stapled to the bottom of the sheeting to allow the hot air to move from lower section, up to the top ridge vents.
It's called "PROPER VENT" or "PROP-R VENT".
Yes, I can only imagine a lifetime of problems if they are spraying foam directly to the back of the roof sheathing. Sheathing delamination is just one.
Radiant barriers don't stop the sun's radiation. They stop the ceiling from radiating downward into the room. Reflective surfaces are bad at emitting energy for the same reason they're bad at absorbing it. You need the air gap because if anything touches it, the heat simply conducts through it (it's metal) and then radiates into the room from that surface. That's why it has to be kept clean.
Thank you, I was hoping someone would correct the OP
Even if it's not clean the emissivity mitigates the heat transfer
Radiant barriers on sheathing do nothing. There has to be an air gap between the radiant barrier and sheathing, but no one wants to deal with the rolls so they just put it on the sheathing to make people think they have a radiant barrier, the don't.
Good luck trying to keep your attic ceiling spotlessly clean!
If I had squatters or bums living in peoples houses nearby. I'd do the foam with it to keep the bums toasty warm in the summer.
@@bobbygetsbanned6049yeap. The other way to install it is the reverse with radiant barrier on the outside and an airspace between it and the exterior roofing mounted on furrings
Yep! 👍🏻 100% true. Excellent video
As a UK estate agent of 24 years, please DO NOT install spray foam. You will not be able to sell it to anyone needing a mortgage. It is very expensive to have removed.
This isn’t an issue in the states. Especially here in Texas. Spray foam is actually sought after because it’s so good at keeping the AC in. Summers here are pretty brutal without it.
Lol that’s not a problem here in the US. It’s actually a value add.
I can imagine, in rainy Britain stuff is gonna rot.
Greetings from Australia. We use rock wool down here. Foam is a fire hazard ... 🇦🇺🙋🏼♀️
@@alli3219 they make fire retardant spray foam but it is more expensive, IMHO it should and likely will in the future be required in most installations. They also make a paint like thermal and flame barrier that can be sprayed over existing foam.
@83ryangreen key word, retardant. Might as well remove ant from it because it doesn't actually prevent fire. It's not fire proof.
Don’t use spray foam. If moisture finds it way in, and it will, it will rot your roof and you’ll never know
Im just gonna go for other insulation personally. Like rockwool or those prefab foam insulation sheets.
I built my house with rockwool batts. Definitely the best decision i ever made in my life. The only reason my house warms up in full summer sun is the windows. And holds in heat during the winter so well i could go naked during an arctic blast. Not to mention how quiet my house is. Sometimes i dont know its raining and hardly wake up from thunderstorms.
Rockwool is more fire proof too!
Get to know r-value. I'm not disagreeing with you, just that there are huge differences between insulation options and many people just think of it as interchangeable. I have used most every type in different applications. And have had to live with those choices, and what I wish I had done instead. No matter what you do, just understand that you probably need to double or triple the amount of insulation you use between the livable space and the non livable space.
Actually, if I had the money and time to do whatever I wanted, I would mount reflective foil backed Styrofoam sheets on the facing edge of the roof trusses creating an air gap. I would either have the reflective foil facing the house and blow insulation in there, making sure to avoid allowing that to fall all the way to the soffits so it wouldn't block airflow. Or, I would have it face the roof and leave the gap without any insulation (so it would reflect back out) and include extra roof vents at the top to create a chimney effect removing the heat from the attic. Obviously you would still need your regular vents to remain unobstructed. All that providing I didn't just seal the whole stock up and treat it like a liveable space.
Rockwool Rocks! Definitely a much better product than fiberglass or cellulose
I removed all the nasty blown in dirty fluff insulation, now im putting Scrim/foil to line the troughs, then im using bats of rock wool, then radiant barrier to enclose it and serve as a floor or allow for some storage,, also i took out all flex duct and bow have sheet metal ductwork,
Also rewiring and making the whole space more proper and issue free.
I'm in Canada, radiant barrier is joke here. Foam or traditional bats, but not aginst sheeting. Condensation will rot you out in few years. Always leave an air gap between the sheeting and insulation.
Properly installed spray foam has a special corrugated foam installed next to the roof decking so that the heat and moisture can be vented from the underside of the panels.
Word
In Texas, the scorching sun and high air temperatures lead to high cooling costs. A radiant barrier *can* be a cost effective way to reduce cooling costs. Just don't confuse it with actual insulation, and make sure it is used properly.
The radiant barrier uses are limited. It is only useful when placed facing an exterior wall or roof. By reflecting the radiant energy emitted by the wall or roof back to the wall or roof, it increases the temperature of the wall or roof, so you have to be sure the exterior material can handle the heat. Asphalt can melt at those temperatures.
If you don't have vented space between the radiant barrier and the exterior, then the heat is trapped, and a large portion of the heat will radiate or conduct to the house, losing a great deal of the radiant barrier's effect. Shiny side facing the exterior with a gap.
With a steel frame and exterior, we use a radiant barrier facing our R panel. The panels allow it to vent, and the panel can take the heat. We have bat insulation behind the barrier in the walls. On the roof, the barrier is hung under the panels, and we have blow in on the ceiling. On a sunny summer day, our roof might melt your shoes, but our attic is a good 25F cooler than an attic with no barrier.
All in all, the radiant barrier is an inexpensive addition that can make a major improvement to summer performance if it's used properly.
As for spray foam.... I can see how it can be useful, but can't see any place where it is either the best choice or the most cost effective choice a a major components in insulation. What a train wreck if it ever leaked from a deteriorated gasket or hail damage! And god help you if you ever have to replace a roof or wall panel! There are cheaper, more manageable ways to get insulation that is just as good.
And I would *never* put spray foam on wood. It may be excellent insulation, but it is also a disaster waiting to happen.
Question for you if you don't mind. I'm in Texas also. By shiny side facing out with a gap do you mean to indicate that it's backwards as shown in this video? The reason I'm asking is because mine is done as shown in the video but I can see the actual foam core backing being a gap. Damn straight my roof could probably melt rubber sole shoes this time of year too.
@@Zarathustran In cooler climates, they put the reflective face toward the interior so it reflects radiant energy back at the house. Double sided barriers - like bubble wrap - is also a thing.
Think about how it works - all objects warmer than 0 kelvin emit electromagnetic waves. The Sun and heat lamps are well known for this, but it's true of all objects, which is how thermal cameras work.
Radiant barriers are very different from normal insulation - the materials used are often conductive to heat.
Normal insulation will absorb radiant energy and warm up, but conducts only a small portion of the heat that reaches one face to the other face.
A radiant barrier often has an insulation backing or center because the barrier is not 100% reflective - so the foil absorbs some of the energy. The insulating backing reduces the heat conducted from the foil to the other side of the barrier.
The reason your roof is so hot is because it is absorbing the Sun's radiant energy. The roof, in turn emits electromagnetic waves (radiant heat) both away from the house and into the attic.
If the electromagnetic energy emitted by your scorching hot roof hits foam instead of foil, then your radiant barrier is doing nothing to keep your house cool that regular insulation would not.
In a correct installation, the radiant barrier reflects the energy back at the heat source (the roof down south - the house up north), which then absorbs the energy and becomes even warmer. With an air gap, the heat source heats the air via conduction, and the hot air escapes the building. Or, in a northern install, the hot air doesn't escape the building.
Something to keep in mind: without an air gap, it's not a radiant barrier, it's a heat conductive non-insulator. aka waste of money.
In this video, it looks like foam board with a radiant barrier. Lots of foam board comes with one side foil faced, these days, so that may just be what they had on hand, and they were not actually intending to use the radiant barrier.
It also looks like the board is pushed up against the plywood roof. If the foil side is pushed against the roof, then it would not serve any function, so they may as well make it face the attic and have some use in the winter (until it gets foam coated).
Is that the case in your installation?
Or maybe a yankee installed your barrier?
Or - maybe you have bubble wrap (two sided)?
With steel construction, my home is very different from what is pictured here. The radiant barrier for my roof is not a face on foam board. They used Solar Guard hung between the purlins. This creates pockets of air trapped against the roof. Because of the ribs in our R panel roof, air caught in the solar guard can flow past the purlins from the eaves to the ridge vent.
There's nothing wrong with spray foam IF it is applied properly and the roof is properly constructed. I wouldn't retrofit it. Go watch some Matt Risinger videos on the subject.
I will never get a house that has spray foam. It can hold water like a sponge, its not fire resistant and is highly toxic when burned. It makes remodeling a nightmare. If you want to spend the money, get rockwool instead.
Hell yeah!!! If my house catches on fire I definitely wouldn't want toxic smoke present. 😅
And rockwool *doesn't* hold water like a sponge? As for toxicity, I wonder how the toxicity of rockwool and foam compare when things _aren't_ on fire?
hmmm, interesting. I don't kniw enough about this to makeba decision.
Spray foam is fire resistant. Closed cell doesn't hold water.
Rockwool isn't toxic sitting in your attic
Radiant barriers are often misunderstood and misapplied. A Radiant Barrier such as Metalized mylar when placed with the reflective surface facing towards the roof will reflect a large amount of the radiant energy that has entered the space and having a very low emissivity will retain a very small percentage of the radiant energy. This combined with an air gap creates a very efficient system.
Unfortunately, you also misunderstand how radiant barriers work. The don't reflect radiant energy back through the roof, they simply are inefficient emitters of infra-red radiant energy into the attic, thus reducing heat flow into the attic.
@@gregben He didn't claim that they reflect radiant energy back through the roof.
Don't use spray foam its a mess that is horrific to sort out if you remodel; max out on the insulated radiant barrier instead
Don't forget how well spray foam burns. In a fire a spray foam insolated house is going to burn faster.
And how it is a nightmare when you get a leak.
... Or that it makes it impossible to inspect the roof structure, for any reason. Like, when somebody applies for a mortgage to buy your house...
@@epicfail5707it's actually the opposite of that. Foam blocks airflow and prevents the spread of fire.
If spary every inch... 1% chace.
The wind still blows when the windows are blew out from the heat of the fire... I got it, i want you to light your couch on fire. Then I want to see you saving your house with foam sprayed on the underside of the roof decking... where you say there no air as you blocked it all.... blahahaha!
In this scenario, the air gap needs to be between the radiant barrier and the roof sheathing if the goal is to radiate heat back outward. The air gap doesn’t have to be much, .75 in.
That said, even without an air gap the radiant barrier is still going to work, just not as well. Here in the north, we install radiant barrier on the interior walls to reflect heat back inwards during the winter. It works great.
Rad barrier should be applied on bottom of rafters thus trapping 6 to 8 inches of air that can be drafted out of attic with thw heat radiated down from the shingles.
Foam isn't cheap AND if done incorrectly can cause humidity problems. Be sure to have a heat load done by a professional so that the a/c can be sized correctly and the humidity can be addressed before it becomes problematic
Exactly, radiant barrier on the OSB defeats the purpose.
What is shown in this video is not radiant barrier.
Some houses don’t have AC
@@YeshuaKingMessiah lol
Put the ductwork in the insulated knee walls of the attic and avoid conditioning the entire unused space up there. Or put ducts and equipment in the crawlspace. Slabs are cheap and not good for installation of plumbing and electrical
The radiant barrier that the builder put in my roof blocks about 90% of all cell signals.
My house in AZ has radiant barrier on top of the roof sheathing, metal frame windows with a reflective metal tint, foil backed glass batts in the walls, nearly a Faraday cage. Keeps out the heat, and cell signals. Phoenix Fire switched from UHF to VHF radios to be able to communicate.
(dons tinfoil hat) SOLD.
You can still get a cell signal inside your home using a booster that mounts outside. But you have more control with what signal you're getting so a lot of noise is reduced for wifi and its harder for those outside your home to tap into your network.
I disagree get a better than a free government phone. You won't have any cell problems any longer. Facts!
That is strange because GSM signal doesn't come from above, it comes from the sides
This is just people that live so far away from a cell tower that they think their tin foil hats do something.
Im a big fan of radiant barrier... In florida!
I bought a sheet roll of it that has holes for ventilation. All you do is staple it to the rafters. No plans to do spray foam though. I think i spent maybe 400 bucks in foil to do a 2400 sf house. Its a great product but it NEEDS to be used properly.
Radiant barrier on the rafters, blow-in cellulose insulation on the floor of the attic
Install furring strips on each side of the truss and then attach polystyrene board (pink foam). You get the foam and an air pocket for the heat to transfer to the ridge vent.
Big brain
@@N_AUD1 Big Brain probably never had to actually work hands on with it . I suggest install tubing at 1.65 parsecs and connecting it to a geothermal venting system with a low pressure hydraulics using depleted uranium . The objective here is thermodynamic mode of elasticity and molecular transfer of quasi-stellar wind turbines that will effectively increase the R-values proportional to the Newton's 4th law of insulation . Always complicate the simple
@@Sjwolosz321this made me spit out my Mt Dew
@@Sjwolosz321
The guy (@joshwiedenbeck6944) is right though, that's why foamboard with single/double-sided foil is sold. You get the high r-value/inch of foam, as well as the radiant barrier rejecting heat into the cavity under the roof deck. If you use common sense in venting that cavity, you get the best performance/thickness of any common roof system I know of.
I'm not a roofer and could be wrong, but I'm pretty sure me & he are right.
I agree with Josh, that radiant barrier most definitely works I built house with both and I crawled around in a house with and without it doing remodeling and fixing a leak caused by the shingles blowing off in a storm and I wanted to check to see all signs of where the water has spread and if I need to do more than fix the shingles and treat the mood and replace drywall.
There was a huge difference with no radiant barrier being inside the attic with no radiant barrier. Plus I like using it when sheeting the roof after getting the trusses done because carrying water logged plywood for two or 3 days all day and bending and cutting and the way your back feels so good after words not to mention the extra weight and walking across the trusses with a full sheet of plywood on a windy day, it's feels alot safer when you are gonna carry one or two bunks of plywood by the time your done along with your partners helping out, it's alot easier to not get blown off the roof I feel with the lighter plywood, I can throw it down faster if a fast gust of wind turns up or set it down for a second alot quicker and brace yourself quickly before getting blown and having to back pedal on 1.5 trusses with a 60 to 80 lb kite depending on if it rained the night before or that day.
But you definitely need the air gap to ventilate right under the radiant barrier, the gap also allows the heat to not transfer directly into the insulation and heat up the attic, think of a tall tree or tall metal flat roof that u see with solar panels on them that they put in parking lots nowadays, the things are like 20 ft or 25 ft tall. If u put ur head right under the sheet metal it's probably pretty damn hot, but at ur head level of 6ft and ur car height, it's way cooler with that roof that high up even with no insulation or roofing just sheet metal and solar panels, even with out solar panels they provide way cooler car temperatures in ur car if it's parked under it all day in 95 degree weather, it's like 75 degrees under it at head height.
But if u use that radiant barrier and insulation correctly and also well placed solar air vents that spin to suck hot air out, you could make a house in 90 weather pleasant with no a/c , just a fan on medium or low if needed and may not need any fan or a/c at night.
You could spend an extra 15 grand on radiant barrier and solar vents and insulation done right and ridge vent and make use of any Dutch gable or just gable to put a big solar vent on the end if each vent on each end and on top, if u put 4 solar vents and ridge vent and bird blocks and maybe a couple cheap metal vents on the side hidden from the curb appeal side of the house to not make it look ugly ir cluttered.
You could do a science project and build a little flat roof dog house and 3 different versions I bet the farm if u did all three the inside temperature of the dog house done right will be 10 degrees cooler and in a house I bet at least 10-15 degrees cooler with all three in hot climates and times that by 365 and the electricity u save per day with less or no a/c possible no a/c in winter months and just fan use and some a/c to sleep or just 2 or 3 hours a day in summer compared to 8 hours of a/c in all rooms all year almost ,
You pay for itself in the first year and when u use the a/c u don't feel guilty or feel like money flying out the window which makes the times when u do use the a/c feel so much better and far more effective especially if it's a day off and u feel like a/c and don't care what it costs because it's too hot and u want to enjoy ur Saturday
Closed cell foam does NOT absorb water at all. It there is a leak on the wood roof surface, it may be dificult to locate because it will not show up in the attic as the foam does not let water go thru.
When I see spray foam my first thoughts are trapped moisture in the wood and rot, the moisture would dry out quickly if the wood has room to breath as my house built in 1935.
In the UK a number of the main banks have stopped giving mortgages for houses where the has been sprayed with foam.
Spray foam in the attic cost me a lot of money replacing rafters.
😂 not ever
Wood has lungs?
@@sequoiapietri5473 I have seen this in uninsulated cottages/homes from the 1930's . Unsealed buildings are remarkable for the longevity of unpainted wood, siding, window frames and even asphalt? shingles.
I did radiant barriers for 6 years. How to apply radiant barrier depends on the climate and what you're hoping to achieve. Like you mentioned in your video, without an air gap, radiant barrier on the sheathing can raise the temperature of the attic-increasing your cooling costs and decreasing your heating costs. Most of the time, the more efficient use of radiant barrier is across the "floor" of the attic space. Reduces the heat envelope of the home and essentially reflects heat back down in the winter and out in the summer. Put in some solar fans, and your attic can be within 10 or so degrees of the temperatures outside which is also good for your shingles!
Radiant barrier on top of the rafters. Rockwool (or other sheet types) at the bottom.
Add to that heat-reflecting paint on the roof tiles to create a super barrier. Only if you don't have winters.
How do you know you have a roof leak with spray foam? Do you just wait for the roof to collapse?
Pretty much
I can imagine having to fix the roof with foam.
For the love of goodness don’t spray foam a roof
Why?
@@YouKnow-yd3zm if you ever have a leak, good luck trying to find the source
And good luck getting it to dry. Will be a soaked mess
Just imagine the mess when it comes time to replace the roof decking, and you've effectively glued it to your trusses.
@@John_McJohnson You got a good point there .. Future remodelers nightmare. But they'll want you to the do the job as if Icynene was never used .
It doesn't reflect heat away, and it doesn't transfer any heat to the air. It's pretty much the opposite.
The purpose of the radiant barrier is to prevent the hot roof sheathing (heated by the hot shingles, which are heated by the sun) from radiating that heat into the attic. It's supposed to keep the attic cooler in the summer, and theoretically introduce less heat into the house and reduce the electricity needed for cooling.
The only thing you're correct about is that it needs an air gap in order to work, and that applying spray foam over it makes the radiant barrier useless.
But that radiant barrier is pretty much a waste of money in any case.
I got a quote for 9k$ for foam I did the foil barrier myself for 800$
That's like saying "I really wanted a Porsche 944 Carrera S4 so I got the Kia Sorento and saved $$"
@@JoeLiberalism More like "I bought the Kia Sorento so that i now are able to afford something else than a overpriced suicidemachine."
I bought the roll of radiant barrier foil. It's like tyvek with foil on it. It was easy to staple to the underside of the roof. It works really well.
So you threw away $800.
@@fugu4163Actually most exotic cars will start to appreciate after a certain amount of time. Old air cooled 911s are worth much more now than they ever were new. Countach's are going for $400k minimum now. However your Kia will eventually be worth zero. Seems like you just have a knack for poor financial decisions.
im surprised no one is mentioning that when sprayfoam is applied to the roof sheathing, it will dramatically reduce the lifespan of the roofing underlayment. it drastically increases roof deck temperatures, because it blocks the heat from radiating through. generally its better to double down on insulation above the ceiling than to try and keep the heat out of the attic. if your building cant breath, you will get mold. even in the hottest climates. vented attic spaces are extremely important.
In Australia we call this Sisalation and its stock standard on all houses that have tin (colour bond) roofs. I’m pretty sure it’s regulation to actually have this with a colour bond roof. Either spray foam or bats are usually installed along with this. Generally not used with tiled roofs.
I had a left over roll from a shed installation where it was used on the roof only. Had enough to cover a sun facing wall and it does an excellent job.
I have the foil in my roof and external walls, and I didn't know we used spray foam in Australia.
@@Never2Late8 Oh ****, I wouldn't wanna be in that house, imagine a bush fire 🔥 😮
Spray foam is nice until your roof is leaking. Spray foam retains the moisture and it is not until it is soaked that a leak will occur.
As a roofer, I’ve seen some crazy things. We recently completed a house where the HO had rotted sheathing, when we cut it out and remove it, the truss came up with it. The foam retained all the moisture and eventually deteriorated the truss. Had to get an entire out for the HO and it up costing them thousands of dollars.
Some insurance companies will cancel a renewal policy because an inspector can not verify the condition of the roof in foam has been applied.
In what county?
In the uk you wont be able to remortgage your house or get a mortgage onna house with spray foam because of that issue. Also it can cause timber to rot
I find it fascinating that in the UK spray foam can invalidate your mortgage and after the government did grants for it at the turn of the century it’s now considered a hot fucking mess to sort out
We have close cell spray foam in our house. It reinforces the structure of the house, so that's why we chose it since we live in tornado alley. Its amazing at dampening sound and insulating. However, we've had roof leaks and it has been an absolute pain to locate the leak source, not to mention the concerns about mold. If i could do it again, I'd make sure we have a way to remove it easily and replace it with sheet foam where needed. Maybe a barrier like this would peel?
Why don’t you use bricks, mortar and real roof tiles with storm clips like we do in Germany. That will last a tornado.
It actually won’t last a tornado, category 4-5 tornados are capable of leveling cinder block and masonry construction
If you’re not underground, nothing will protect you
@@MatzeMaulwurfThose don't help much when the wind speed is faster than the top speed of a Veyron.
@@AvoCattoTV for sure it helps. Search for „BMI Windsogrechner“. You can calculate everything there. If the roof is made well, 180km top speeds are no problem.
Km/h
If that silver layer is in direct contact with the sheathing, it's installed incorrectly: it does NOTHING for conducted heat (i.e. shingles>sheathing>foil). It MUST have an air gap on BOTH sides, as it reflects RADIANT heat (wow, it's even in the name!). But you need a material transition for it to become radiant heat (i.e. hot solid>air>radiant barrier) to do ANYTHING. I stapled radiant foil on the bottoms of my rafters, leaving air gaps at top & bottom for airflow & cooling for the backside of the sheathing, and you could feel an immediate drop in temps below the barrier.
You need at least 1" gap to make a radiant barrier work. I have a decoupled walls on my 1st floor and laminated silver foil rigid insulation onto the block walls, allowed a 1" gap and then framed walls that are conventionally insulated. This works incredibly well.
The ideal solution is a trifecta:
~ radiant barrier to shed heat from the roof
~ those gussets/channels to provide a 2" deep channel
~ spray foam to insulate the attic from the gussets
While the gussets are sometimes used by themselves, they have two key flaws: thermal interaction with the sheathing and no tangible R-value. The radiant barrier addresses the first while the spray foam (mostly) addresses the second.
Aren’t you supposed to use an air chute with a vented attic anyway?
Biggest problem of spray foam in south Florida is the moisture build up in your attic because spray foam literally seals it up hermetically. I’ve heard horror stories. My HVAC installer who said a customer who sprayed foam was having major issues with the ac ductwork completely drenched from all the condensation build up and ruining all the ceilings in the home. Also a roofer I know said he’s seeing problems with the plywood turning soft from the built up moisture inside it. I have a very large home and what worked excellent for me was insulating the ceiling with blown in highest amount possible and then I installed a commercial kitchen roof exhaust fan on a timer from 10am to 6pm in the summer time. This worked like a charm, we were able to do all the attic electrical and HVAC without breaking a sweat.
We've got a walk in uninsulated attic that I'd love to turn into living space but I don't want to put foam insulation in the rafters. It's a 120 year old house and I'd rather not do something that is impossible to undo.
@@_-0_x_-_p_0-_ Oh, the rafters are straight as an arrow. It's all number one full dimension 2x6's and the best stuff I've ever seen. What it isn't is consistent in spacing. 16", 17 1/4", 15 3/8", and so forth. I've looked at the styrafoam/fiberglass and that's likely how we'll go. I'd like to do a cold roof with the air channels just on the underside of the decking - which is doable as the eaves can be opened to vent into the attic, up the roof, and into the area of the attic above the 7' height where there are already cross braces, and out a ridge vent. But that's too big and complex for me to want to do.
@@_-0_x_-_p_0-_ Oh, I bet, hardly anything is flat, level, or plumb in old houses. I can handle the wonky spacing though it sure makes everything more of a custom hand fit operation. The one that annoys me is the floor joists in the attic, they are consistently on 16 1/4 centers. Someone must have used a spacing stick that was just a little off.
@@_-0_x_-_p_0-_The rafters won’t be 2x4’s either
Foam paneling can be removed. It needs to be installed well, and it'll take about 4 inches off the height of your attic's ceiling once installed, but it's held in place with long nails and has tape between the gaps, with a radiant barrier underneath. 4 inches of that insulation should rate approximately R20-R30, depending on what was used.
It's pricey to have installed professionally, and it's a pain in the ass to get up into some attics, but it does work.
Use this stuff or rockwool. Rockwool is like fiberglass but it also insulates sound.
I've pulled cable through an attic that had been spray foamed in the rafters in Texas during the summer. It made a tremendous difference in the temperature of the attic. Even without the attic being air conditioned, it was cooler than the outside air.
During the summer my Gf ceiling got really warm. So I went up to the attic and notice there wasn't much blown in insulation in the attic. So I added an additional layer of R13 insulation, vented the attic by installing wind turbines to the roof, and ceiling fans in all the upstairs bedrooms. Years ago it cost me about $1000 in material and several days to do. Saved big bucks on not having to run the AC or heater as much and added to the value of the house.
Powered attic ventilators are a mistake and just draw conditioned air out of the house. Passive vents are enough.
@@rsmith02 True, but I live in So. Cal. so I get the ocean breezes. I don't run the AC very much. I have 3 wind powered turbines on the roof so there is no power usage. Power ventilation in the attic is used only in the evening for a couple of hours when the temps are below 70.
Spray foam is a great place for termites to hide and eat the wood without being seen.
I work in pest control and I see termites living behind anything stuck to wood. Maybe it's okay to spray foam the attic but don't do it in a crawl space at all. Get a moisture barrier that comes up the walls 6" and leave the foundation bare so we can see it. It helps to seal the crawl vents and every penetration and install a dehumidifier. That keeps the air dry so bugs don't like it. It also makes your house healthier.
Spray foam is a disaster, it damages the roof and remders the house unmortgageable.
How so? It looks like it would be a real mess if you had to reroof your house but is there another reason?
Not true in most of the world
@@joet7136 Because the inspector can't tell if there was water damage from leaks. It won't pass inspection for a V.A. loan.
I would never use spray foam. Stuff is a nightmare to remove when shit goes wrong. Your roof deck needs to breathe. Nothing wrong with insulation and soffit vents and a ride vent. If the decking gets wet it can dry out. Spray foam will keep the moisture locked in.
As a framer of nearly 30 years, I always felt the radiant barrier should be installed face up. If you ever stepped on a piece laying on the ground face up, you'd understand it's where all the real work is done.
It is a radiant barrier, not a conductive barrier.
Take 2 sheets of OSB, one with foil, one without. Place then on the ground in the sun. The foil faced sheet will heat up slower, because the foil reflects a lot of heat. However the foil faces sheet will eventually get hotter because the foil slows down thr rate at which heat re-radiates from the board (emissivity)
Spray foam, air gap, and then Reflectix on the inside can increase the R value and reduce cooling costs by 10%.
Install spray foam in the UK and it immediately makes your house unsaleable as most mortgage lenders won't lend on a property with it on
Weird as all new houses in new england and canada are foamed. Its the new standard
Ive never seen that in Germany either, i think its not approved by anybody. And how americans build houses is insane... paper thin walls, no insulation under their floors, no insulation between rooms, single glas Windows
@@CookieMonster-vn6zb Dude you're 100 years late. I'm a European and I live in the US and houses are built super well these days. Yes the walls are framed in wood but they are pretty solid due to the way they are engineered together. Unless you're building a bunker in a tornado area this is appropriate. Most places don't have tornadoes in the US..... As far as insulation and various building components they far exceed Europe at this point. Insulation is super thick, VASTLY more than most existing houses in Europe (on par with new construction in Europe). Windows are triple pane these days. BTW insulating between room doesn't bring energy benefits, only noise insulation IF you need it. Most people don't. Bottom line is you're just another kraut trying to trash non-german things without info.
@CookieMonster-vn6zb where do people get these American stereotypes? Since I started construction 20 years ago, I've never seen a new single pane window installed, our thinnest walls are framed in 2x4 lumber and are about 4 inches thick, we absolutely insulate under floors unless the crawl space or basement is a completely conditioned area and in that case the walls of the conditioned space is insulated, and insulating interior walls does nothing for efficiency and if only good for reducing sound which may people do for that reason but it isn't mandatory.
@CookieMonster-vn6zb double pane windows were literally invented in America. I'm not trying to be offensive, but I believe a lot of the things Europeans make up about America comes from a strange inferiority complex.
Each layer serves its purpose plywood aluminum backing and foam it's a triple layer of heat reduction which in the end in overtime will save you in multiple categories
What I did was bridge the wood heat gap, put radiant foam sheets on the rafters and wood, and then spray foam over the foam. My attic temp in GA is ambient to whatever the house was set to, minus three days. My house sits at 70 degrees. My roof has zero moisture.
That you know of.
@tinacarter8785 yes, that I know of. And I don't have a radon leak. That I know of. Because I check it all the time.
The foil was misapplied in the first place. It should not be applied to the bottom of the sheathing. It should be applied to the 2 x 4 or 2 x 6 rafters away from the sheeting in that way, it will reduce the heat and you won’t need any spray foam.
Just install PIR with batons to leave an air gap…
Spray foam is the death of roofing and can cause many long term problems…
I don't disagree, with a typical roof. But in a flat roof situation, some roofers want a closed cell foam to prevent moisture from getting to the decking. Especially with hot to cold transfer.
@@Black_Dirt_Contractorif it’s a hit roof, spray foam is probably ok, just can’t do it on a cold roof that needs any type of ventilation.
I’ve just had to redo my entire roof that had really crap “wool in plastic bags” installed, it’s a cold roof in a home built in the 1800’s, so i’ve had to batton it and use PIR for best insulation, but still providing that breathable airgap. It’s been “fun”… 🤣👍🏼🤣
Radiant heat is what the foil is for. No one pays extra for the foil except the builder only because it's required by code. Foam is for conductive heat. It is not a waste to have both. The issues using foam on your attic is far more troublesome.
Spraying foam on the bottom of the Roof deck is a HoRRible thing. Do not do it. It will ROT the roof deck Off. Its closed cell foam that means "No OSMOSIS".
12:00 not all putty pads are fire pads. In my experience, if it’s red it’s a fire pad, if it’s grey it’s a sound pad only. Fire pads are only necessary for fire walls (in my neck of the woods), and for fire walls you should also be using fire caulk to fill any cracks or holes.
In UK lenders are refusing mortgages with properties that have been spray foam.
Impressive that in the land of usury they'd refuse
@@TheOneTheOnlyToast >ijits
International journal of islamic thoughts
have used radiant barrier AFTER both spray foam (first) in the cavities, topped off with 2 inches of fiberglass, 1x3 slats topped with radiant barrier then another 1x3 run of slatting so there is an air gap between the ceiling material and the radiant barrier - theory is to help radiate the heat back towards the living area (cathedral ceilings)
Why would you put the toxic waste liquid into your house?
I’m been in the hvac and building science industry since 1986 and have seen both closed cell spray foam and radiant barrier in action. When it was time for me to reroof my home I opted to go with radiant barrier OSB and wait a few years before installing R44 insulation just so the I could measure the difference. I also have a whole house fan. The radiant barrier dropped was worked out fantastic and my attic doesn’t get above 100 degrees F, in the past it would get as high as 130 F. And heat that is built up during the day gets exhausted in the cool evening with my whole house fan therefore the heat never builds up (stored energy).
I live in Phoenix, Arizona. Plumbing is in the attic. We had an attic temperature of 157 degrees my first summer here. Scalding water that you would have to run for minutes. I looked at both, went with spray foam. It is amazing the difference that it makes. Wouldn't change a thing.
Why not use split foam insulation for the pipes?
@philsmith2444 pipe insulation isn't very effective. Could just cover with bats
You need to determine what type of attic space/roof system you have. Open or closed attic/roof system. If you have an open attic/roof then the ridge vent and the soffit needs to be installed correctly. The attic needs to have cooler air enter the attic throughout the soffit and exit through the ridge vent. Adding spray foam to an open type of attic/roof is a mistake. The stored heat in the roof will destroy the roof shingles. You will also cause a moisture issue in the attic. A closed system keeps heat out. There is no air movement. That this system you want to heat and cool the attic space with a thermostat set 10-20 degrees higher or lower than the rest of the house. The type of roof will determine which system is best for the house
I own a roofing company and I’m telling you do not spray foam your tresses unless you have baffles in them. The roof sheathing has to have air circulation or you will have problems and it will cost a fortune to replace rotted wood stuck to foam. Not sure if it works the same for walls.
You're _so_ close.
Radiant Barrier is used to reflect heat back to the place it's coming from. In order to do that, it needs to have an airgap between it and the direction the heat is _coming from._
Radiant barrier facing the attic keeps heat inside the attic. Radiant barrier on the underside of the rafters reflects the radiant the heat from above the rafters back up, and reflects the heat from below the rafters back down (keeping the attic warmer).
So, you're right that sprayfoam on the radiant barrier kills its usefulness, but not _why_ it kills the usefulness.
In practice, materials that are reflective also have low emmisivity. You don't reflect the heat back, you reduce radiant transfer into the attic in the first place. Good try with your reasoning, but you are mistaken. You can point radiant barriers into and out spaces, and the effect is pretty much the same. Heck, radiant barriers in the middle of foam still do a good job of stopping radiant heat transport. Its just that even with insulating materials, conduction is much more efficient than radiation over a short distance.
That radiant barrier doesn't work anyways. The airgap has to be between the sheathing and the barrier, since it's touching the sheathing it does nothing.
You don't attach it straight to it.
@@stevepest4143 Idk what you mean, the radiant barrier in this video is a coating on the OSB sheathing.
@@bobbygetsbanned6049 did you notice him talking about the gap when the illustrations came up?
@@stevepest4143 Yeah he talked about it, but not correctly. The radiant barrier has to have a gap between it and the sheathing, if it's touching the sheathing it won't work.
@bobbygetsbanned6049 true. Which was shown in both the diagram and mentioned verbally.
Radiant barrier on the back of the roof sheathing is a waste. Like you said you need that gap and that gap would be the rafters. If you're going to use spray foam it should be the closed cell spray foam. You also need baffles to help guide the air from the soffits. I would also put the total equivalent of R60 in the attic, along with air sealing it.
When I was doing construction years ago I thought about a system where the radiant barrier is stapled to the bottom of the rafters and use a ridge vent. Keep the soffit vent open to the space in that radiant barrier and let that air flow in and up the inside of that barrier under the roof. The air travels up to the ridge vent and out taking heat from the roof with it. Then use a standard gable vent or powered vent to ventilate the attic. What do you think of this idea? I even got fancy with my idea and ran water lines in there to be pre heated for the hot water system.
Genius!
Absolute optimum is as follows:
Hot side
Air gap
Then Radiant barrier (to reflect radiant heat)
Then High R insulation (to slow conductive heat)
Moisture barrier between hot side and structure (e.g. between roof and rafters in hot climates, or between living space and joists in cold climates)
Air barrier somewhere (to block heat convection, i.e. to keep hot air from moving to the cold side and keep cold air from moving to the hot side)
N.B. You can have two, alternating hot sides. In that case, you want air gap, radiant, insulation, radiant, air gap
@ Thanks. Is that the same for the southwest? Here in Vegas it gets to 120°+ in the summer and we have tile roofs.
@@grumpy3543 the only difference from place to place is which side is the "hot" side.
Heat always moves from hot to cold (on an atomic level, think of it like a "hot" cue ball or bowling ball adding motion to a "cold" rack of balls or pins; the moving ball can change the rack, but the stationary rack does nothing to a ball that is misaimed).
Heat has only three ways to move (in order of importance to keeping houses comfortable):
--Convection: the hot things moving. That's why fans are so good at keeping you cool: they move the air your body has heated away. Walls mostly block this, but the better sealed the envelope of the building, the better it maintains the temperature.
--Conduction: hot things touching one another. That takes time, which is why even entirely metal fire pokers aren't as hot at the handle as at the business end. That's (most of) what insulation blocks.
--Radiation: a small amount of heat transfers via (invisible) light. this is why/how IR cameras work and can tell how hot something is: the hotter it is, the more it radiates. The more light something reflects, the less it absorbs to heat it up. The reason you need an air gap to make radiant barrier work is that the only radiation that makes it through is that which doesn't hit something else along the way. There aren't many molecules in air, there are in liquids and solids. This is relevant to radiant barriers in that the radiant heat they reflect can't go anywhere, and just gets conducted back into it.
So, yeah, the design I shared works everywhere... so long as you know which side is the "hot" side
@ Thanks. Entropy is the key. I love to see new designs to save energy and make it more comfortable
Be sure to make sure your spray foam installer is using the right foam. The problems in the UK stem from people who do not know what they are doing installing the wrong product or installing it incorrectly and causing issues that can cause your roof to rot
Radiant Barrier decking was designed to reflect the heat back upward that's why in real hot climates it causes the shingles to buckle. So insulating it with spray foam does not matter
False. The radiant barrier decking simply reduces the amount of heat flow from the already hot roof into the attic by reducing the amount of infrared radiation from the aluminum surface on the inside of the attic.
We’ve had radiant barrier on our roof for the last 25 years and it’s worked excellent and we’re gonna apply it again on another roof. It’s really up to your discretion on what to use, but it does bring down the heat in your attic or now that we turned our attic in loft
Until you have a roof leak that you didn’t know about; and now you have rotting boards from the water sitting between the foam and sheathing for years.
It depends on the foam type.
You missed the part where radiant barrier isn't intended to be used by itself, but with fiberglass or mineral wool bat insulation installed a couple inches off the surface of the radiant barrier. There are three modes of heat transfer: Radiation, Conduction, and Convection. The radiant barrier has very low emissivity and is designed to reduce the amount of radiant heat transfer into the building from the sun beating down on the roof. It does not, however, reduce conductive heat transfer (which is what insulation is for), so if you touch it all of that heat will come through to your hand or to any insulation you put up against it. In most cases a properly installed radiant barrier with bat or foam board insulation installed with the necessary air gap will keep the attic cooler than spray foam. It is also far easier to detect leaks and to make roof repairs than when you use spray foam. Also, if you live somewhere that gets cold in the winter and hot in the summer, the expansion and contraction of the wood framing can cause the monolithic rigid spray foam to crack and separate from the wall.
Every product has it positives and negatives, but unless your house is in a very specific climate and is designed appropriately for it, I wouldn't use spray foam in the attic, especially on the underside of the roof. It is excellent for below slab insulation and for insulating basement walls when installed correctly, and can also be a great choice for difficult to insulate areas and to help make that air barrier transition from the basement wall to the wood framing. However, it is not the best choice for every place you need insulation, and is more often than not the wrong choice.
Foam holds heat and moisture
No, use radiant barrier to reflect IR energy. And use an airgap with a high R insulation after the airgap.
Do not use either it's all about the airflow because it's not just about the heat but also the moisture the most important thing is moving the moisture to prevent mold also many shingle manufacturers say if you use spray foam underneath the roof deck it will void your warranty. Spend the money on doing it on the ceiling space Best bang for your buck.
Technically not correct. Best performance would be to have a radiant barrier system with spray foam. LP tells you how you can do this.
Insulate your living space from the attic, not your attic from the roof.
You and I inner stand that spraying foam on the roof substrate is a Terrible Idea.
If you have HVAC equipment, you need to insulate the roof to protect the equipment from unnecessary wear from the blistering heat or from leaks when it's below freezing. Think of your attic like a vestibule, if the roof is properly insulated, it won't cost as much to heat/cool the 2nd floor. If you're only insulating the floor of the attic, now your 2nd floor is going to require more energy to heat/cool. Pay monthly bills for the extra energy required or pay for insulation once? Keep in mind that outside the roof it might be 100° but inside the attic it's 150°. You're fighting more extreme temperatures if you're not insulating at the roof. Spray foam or insulation batts? Your call.
@@notjamesiha I don't understand why people use foam when there is wool, that thing breaths and correct use of foil works wonders, esspecially with HVAC stuff... I'm a euro', We use wool extensively on roofs of houses - it keeps the house warm during Winter, cool in the summer.
Also great point about costs, that's the only reason I increased My insulation, it decreased the energy requiered for heating by 20kwh on an' average Winter day 😅 + 11kwh on cooling during summer.
All with just a foot thick, decent wool, previously there were 4 niches of trashy poorly installed and worn down Glass wool.
Return of investment in 5yrs was the theory, energy went up enough, along side instalation and material costs - it will be 2yrs tops.
Greetings
do both.
Comprehend is a much better synonym.@@peterparker9286
WARNING!! my father has problems selling his house after having spray foam in the Attic.
apparently the foam rots the wood. I don't know the total ins and outs of it but check first it's compatible with the wood.
Spray foam is 100times better I have it in my attic and the temp in my attic year around is always 10 degrees different from the temp in my home. Spray foam attic is 100% the way to go.
A lot of Mortgage companies are now refusing to mortgage homes that have been spray foamed as they can't inspect the roof structure once it has been covered..
Radiant barrier >spray foam . I'm gonna assume you have a spray foam buisness 😂
I’m gonna assume you don’t know when to use > vs
@JimBobby2006 🎯
1000%
@@Juanhernandez-k8q6r Nope - Thomas is correct on the math
Where I live we don't spray the spray foam up against the sheeting where the shingles are we have our 30 in the ceiling of the house and then the attic space we just leave alone Now if you have an attic space that can be finished then we will insulate up against the sheeting where the shingles are because that's going to be the ceiling of the finished attic space but generally if you have a regular house with a 4/12 or 5/12 pitch roof we just put an r30 in the ceiling of the house and then we put baffles against the sheeting then we will use perforated soffit where the overhang is and that allow air to go up to the ridge vent.
So here is a FYI in England banks don't loan money on homes that have Been spray foamed
Reflex against the roof sheathing and then over the joist allowing for a barrier to be put in place with a 21R factor. Works just fine and lowered my heat in the attic by 15 degrees, easy to repair and install. Spray foam ha toxins and is harder to replace if damage should happen.
😂10,000 dollar toilet.
That also looks _extremely_ uncomfortable to sit on.
They are out there if you want one.
If you plan on living in your attic then insulate the roof rafters. If not just insulate the ceiling joists.
Don't use spray foam, it contains formaldehydes. When your roof leaks and it will, good luck with spray foam.
Wood will not dry and just rot.
A real man with money to spend will skip all that and go straight to vacuum insulated panels
So if sofet vents are installed correctly and insulation is stapled to bottom of roof rafters the air gap is perfect with ridge vent is included this will out perform the rest. If you add gable vents this even make the system work better.
Why anyone would use spray foam in 2024 is crazy to me.
Maybe you just don't understand foam.
The required air space is between the barrier and the roof, not the barrier and the attic. The barrier is supposed to droop to allow a small airspace between it and the roof boards. Expanding foam will press against the barrier and remove that air space, and that's why you shouldn't foam directly over it.
SPRAY FOAM IS A RIPOFF!
Absolutely
While I agree the radiant barrier does very little during cooling season, it does lower heat loss during the winter. The problem with radiant barriers is that you have to clean them: dust, which can attach even on the bottom, reduces the reflecting property. Depending on the coating, oxidation can also reduce reflection.