Metal Roof Installation Over Existing Roof Using RoofingFoil To Reflect The Heat- DIY System
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- เผยแพร่เมื่อ 3 ต.ค. 2024
- www.roofingfoi... DIY Do-It-Yourself One of the most common roofing application for metal roofing is to put your new roof over your old/existing roof. This video shows you how RoofingFoil™ + Underlayment works to reflect heat when you have an air space in your roofing assembly to give you a cooler home with the same amount of work!
Learn more about RoofingFoil™ here: www.roofingfoi...
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Thank you
😎 We used foam sheets with the reflective side up on our roof. The temperature in the house is already staying much nicer than outside, and we still need to add the interior fiberglass insulation.
The foam and foil works fine. However, in a vented attic the foam is basically doing nothing when installed on the roof. The foil is doing all the work. Putting foam on the roof of a vented attic is like holding a jacket over your head. Why?? On a Non-Vented attic it will add some r-value. www.RoofingFoil.com I use a refrigerator example. The door has r-value UNTIL you open it and allow air to flow on both sides. Same for a vented roof.
@@AtticFoil Thanks, good point! We went back and forth about whether to do a vented or unvented attic. We decided on unvented.
What if you've got vaulted interiors?
Great video! Wish I had found it sooner. Just had metal roof installed and the guy installed the radiant barrier insulation but he put the metal roofing directly on top of the radiant barrier. No space in between. Radiant barrier is probably worthless huh? I live in southeastern NC and it gets very hot. In fact it's already hot.
Yep, really no benefit without the airspace. At this point your best bet is to install www.AtticFoil.com inside the attic. You may also want to check your contract. If they say they are installing a "radiant barrier" and did not create an airspace you have a solid case against the installer. Radiant heat by definition is heat transfer ACROSS an airspace. Without the airspace you cannot (by definition) HAVE a radiant barrier.
The thing is you're going to negate 80% of the benefits of that for a while if you put black metal roofing over the top of it because that's going to get very very hot.
Respectfully disagree. TRUE the roof will get hot. But, with the airspace there is VERY little conductive heat. For heat to get across the airspace it MUST convert to radiant heat. And, when this happens, we OWN it!! Since the www.RoofingFoil.com reflects 97% of the radiant heat. You can go in this attic on a hot-sunny day and not know if the sun is shining or not. With this system the color of the roof makes very little difference.
It blocks the heat that radiates. From all colors. It works even better than expected.
At 1:45 in the video you imply that the new roof will go over the existing older shingles (that are in good condition).
My question: If my roof still has about five years left on it does it make sense to leave the current shingles in place, and then place foil on top of the old shingles, add the wood sheathing and metal roof on top of it all? That should reduce the labor cost of a new roof. Are there downsides to this approach?
Adding another deck is a pretty big deal as far as weight. Not sure why you would need a new deck with battens and a metal roof combined with www.RoofingFoil.com
Could I install this on my single story black felt and tar roof to keep it cooler? Could I glue it down and not worry about it lifting? If so what glue would be best? Mid afternoon to early evening the heat starts coming into the house. 😊 Thank you.
Glue? Not sure how it's going to lift with roofing cap nails and/or battens? What type of roof are you going to install with the www.RoofingFoil.com product?
Glossy side towards sunlight?
Yep, foil side up. That's how www.RoofingFoil.com works to keep radiant heat out of the attic/home/building.
There must be an air space on the downside if it installed to cool the home. It appears that there is no air sprayer below it but that it's installed on a solid surface.
Air space on either side working off either reflectivity or emissivity. Here is a video to explain it: th-cam.com/video/uGP5KobU6R4/w-d-xo.html
@@AtticFoil Thanks. So, according to the video you linked to, the barrier works on the roof or in the attic attached to the bottom of the rafters creating an air space between the barrier and bottom of the roof, and attached under the roof, the barrier reduces heat transfer by about 50% through reflectivity and on the roof the barrier reduces heat transfer by 30% through emissivity. Thus, if only one barrier us used, attach it to the bottom of the rafters, but better yet, attach one at both locations. A white roof would further add to the savings by reducing the amount of heat transmitted from the roof.
@@jzwillows The 30% is for foil applied directly to the roof decking (facing into the attic) Putting on TOP of the roof www.RoofingFoil.com would be well above 50% but have not seen any full scale tests to quantify the amount.
@@AtticFoilAccording to the video you linked to (1:35) and the US Dept of Energy 2012 study (available online and quoted in Wikipedia radiant barrier article en.wikipedia.org/wiki/Radiant_barrier in Roofs and attics section) the barrier is most effective (50%) when there is an air space on the hot side (thus when attached under the roof), not when the barrier is on the roof (30%). However, it is still not as effective as a white roof according to the article.
@@jzwillows Be clear that these are two totally different applications. The DOE was for different methods INSIDE the attic. Either attached to the bottom of the decking 30% OR stapled to bottom of rafters like www.AtticFoil.com at 50%. With both of these methods the roof deck STILL gets hot, but different amounts of heat transfer to the floor of the attic. This video is about putting a different product www.RoofingFoil.com on TOP of the roof deck -a DIFFERENT application. With this method the roof deck can easily be 20º cooler than with below/inside the attic. Like I said, I've never seen any full scale tests, but common sense says the further to the outside you can get the radiant barrier the less heat will get though. Unfortunately, this method us limited to only when a new roof (usually metal or tile with an airspace) is being installed.
You use 2x4's for the battens, could 1x2's be used instead? I will be using the same style steel roof. Would the 1x2's provide enough air space?
Yes, most customers use 1x4's. 1x2's will work also to install www.RoofingFoil.com
Thanks for the quick reply!@@AtticFoil
I have rotten leaking roof. Can I put metal roof panels ?
Rotten?? Probably should replace/fix rotten area before installing www.RoofingFoil.com and a metal roof.
There is a space between the foil and the metal roofing sheets. You havent said what this space should be optimally. Or could this space be omitted? That is by installing the roofing sheets directly on the foil with no 2x4 (Which will defeat the barrier). I dont see this being properly explained. In many places there is no ply decking, Laths run across on the rafters exposing the underside of the metal roof in the attic. Any special considerations for this. (I live in the caribbean and this is how roofing is constructed).
We mention many places at www.RoofingFoil.com you want a 1/2" space or more. But bigger does not really help. We sell for these type roofs in the Caribbean all the time. We have sent just a few rolls and full crates for a whole development.
Question:
Can this be installed on an unvented (hot) roof? Cathedral ceilings, r-30 fiberglass batts, no ridge vent or soffit vents.
Absolutely! Non vented attics are great! Whether you use fiberglass or foam. It's like building a refrigerator. Now, let'd put the refrigerator in the shade!!!! It will effective double the r-value when the sun is shining. Use www.RoofingFoil.com as your first line of defensed against radiant heat and the fiberglass as your second line of defense against conductive heat. We have many home builders use it with non-vented attics in combination with metal roofs.
I'm sure this will work but contractors are reluctant to use battens and prefer to tear off the asphalt. I guess there is risk of walking on it, and possible hail damage. Even McElroy Metal admitted that the air gap worked but contractors would charge 20% more to install on batten decking. Is it much more difficult to install metal over battens instead of a metal deck?
This video is not about what's cheapest. It's about what's best. This method usually pays for itself over time. www.RoofingFoil.com combined with battens is the "best". We have many high performance builders use it on every job.
Don’t you need spaces in the battens to let the heat ride up to the ridge?
Most metal panels have ribbing which provides plenty of ventilation. For flat standing seam type roofs, just leaving some gaps between the battens will provide a path for ventilation. The www.RoofingFoil.com works to reflect radiant heat with ventilation or with a "dead air" space in the roof.
can we do the insulation for the sheeting done already?
Please clarify. Don't understand your question about www.RoofingFoil.com
@@AtticFoil small farm house was built with metal sheet similar to the one in your video, but without any heat barrier in mind that time. How can we install the insulation without removing the sheet now?
Yes, it depends on your goals. If you ONLY want to reflect heat, you can install www.AtticFoil.com on the bottom of the rafters. Basically treat it as an "open" attic. Of, you want to reflect heat AND control condensation, then look at our metal building products here: bluetexinsulation.com/pages/existing-construction-wood-framed-buildings-installation
Would using this along side a 3/4 foam board between your perlins be benifical or just use the foil no foam board?
Only if the attic is NON-Vented would this help. Otherwise it's kinda like comparing a thick umbrella to a thin umbrella. No additional benefit. Typically, in a vented attic, I'd install www.RoofingFoil.com on the roof deck and then more attic insulation on the FLOOR of the attic where it will actually help.
is the main insulation underneath the plywood at 1:25?
The main insulation is in the attic on the floor. This is a typical ventilated attic.