Excellent job on the video. You deserve a bigger following! I am also in Upstate SC. Currently getting ready to build two houses on twenty acres my son and I are developing for a small homestead for our families. We are doing a very similar crawl space. This is very helpful!! I like the idea of sealing the top of the wall against moisture. So many people feel I am waisting my time doing all this extra work. To me its just part of what needs to be done especially in our humid climate. I have been an electrical contractor and in construction most of my life. You doing this to your foundation tells me your top notch and its highly likely every aspect of your homes is top notch as well. Wish more people cared about the details. You get an A+++!!! Terry
Thanks so much Terry! Glad the videos are helpful! That's our goal!!! Like and share us to help get the word out. More education is needed in the industry. Sounds like you're doing it the right way and it will pay huge dividends over your lifetime in the house and the life of the home! We run into folks who think its a waste of time frequently but the awareness is building and more folks understand why building better on the most expensive investment most of us make is a very smart decision! Once people have lived in a better built home, they are completely sold on the results. If we can help with suggestions on your build, don't hesitate to reach out!
That is so true! Our founder enclosed his first crawlspace on his 1970's built home 18 years ago and learned first hand how beneficial encapsulated crawlspaces are as well and how difficult encapsulating after the fact is!
So glad to have you follow us! We’ve known Matt for years and, like he and the build show team, we enjoy sharing our experiences with the world in hopes that it’s helpful for folks and provides a better understanding on east ways to build better! If you’re ever back in SC, reach out!
Great question! I always use the “think like a shingle” mantra which you have to think about upside down since we are concerned about potential water from underneath. So, the membrane on the floor is lapped on top of the membrane coming down the foundation walls. Laps on the floor membrane will depend on the slope of the Crawlspace floor. If water were to flow beneath the membrane, we want to avoid water “catching” a lap from beneath bringing the water to the tape seam above. Let us know if this makes sense. If it doesn’t, we can make a quick video to illustrate.
Outstanding video (my lot is amazingly similar with lake view to yours here) - I am in Climate Zone 4 in Northwest Arkansas, nearly Zone 3. I'll preference my three questions with, I am not a builder: 1) Why do most of your sill plate bolts appear bent, or is that tape covering them, and 2) Will you be installing a termite shield? 3) What is the waterproofing liquid being used and is it just a standard product? Thanks - my new home foundation is going in now and I am having a heck of a time communicating to my builder to do similar to your installation here in my crawl. I need to get to some agreement with him before he gets to the sill plate.
1) I think you're seeing our foundation "straps" which we use instead of bolts. These are embedded in the foundation and bent around the framing and nailed to the framing in multiple holes. We find that the straps can not only hold the sill plate, but run up the wall and attach to framing as well. 2) We install termite shielding on our insulated stemwall slab foundations which we will be discussing in some upcoming videos, but do not install specific termite shields on our crawlspace foundations. We treat all of our homes with borate termite treatment applied to the wood framing 3 feet in all directions from any contact with masonry or concrete. 3) The waterproofing is a standard asphalt-type emulsion.
Is there a reason NOT to pour concrete for the crawlspace floor? I mean other than cost, obviously. I'm adding a 900 SF rectangular addition to my home. I think I would like a full concrete floorspace with about a 4-5 foot depth. I mostly want sealed environment storage. Am I wasting money? Is your system a better way? I watched the other video with the finished-out area and it does look great.
Great question. It definitely an option for an encapsulated Crawlspace. Just need to insure that the vapor barrier is continuous under the concrete and sealed to the foundation walls. The concrete is more expensive but makes for a super nice space! You can actually pour a thinner slab (2-3” vs 4”) since it’s not going to have heavy traffic. Please send pictures if you pour it!!
So, for encapsulated crawlspace, built from the beginning as such, you wouldn't just build it the way a pool is made? I was watching video I took of the construction of my pool. They dug the hole with a skid steer. Put down rock. Compacted it. The put rebar down the sides and across the middle. One giant wire mesh everywhere. Then they started blowing concrete. No barriers! Is that because you dont care about moisture with a pool? Lol @@AddisonHomes
@addisonhomes Also, could you use galvanized steel posts instead of concrete & rebar columns? You know, like they have in a warehouse to hold up the steel beam ceilings.
Why is there no termite inspection gap in a finished basement? When are we going to get the codes updated for a crawlspace built to this level. Seems like a gap is not needed if the inside of the crawl space is going to be built that well. Next question why not water proof under the footing to stop moisture flow from the bottom instead of letting g it wick all the way up the block wall?
Great questions: - The termite inspection gap is impractical on a finished basement since it is typically inaccessible when a drywall ceiling is used. For a lay-in tile ceiling, the top of the wall is accessible for inspection. - The gap is needed for a close crawlspace. Without the gap, there would be no way to see if termites were tunneling up through the foam insulation board. - Waterproofing under the footing is more challenging than it sounds. In the Southeast, we typically dig a footing trench and fill it with concrete. In order to waterproof the footing, we would need to line the trench with a moisture barrier and ensure it gets wrapped around the footing. Realistically, it is difficult to ensure that this barrier is 100% and also difficult to ensure that rain/moisture doesn't soak into the masonry wall above the waterproofing and wick up to the framing. We have found that the spray applied sealant is extremely easy to apply to the top of the wall while our waterproofing contractor is on-site spraying the exterior below grade foundation walls. There is a product that @jake.bruton.arrow.building covered in a recent video that is actually a footing form that potentially doubles as a waterproofing footing wrap.
Love your video. Im a new builder and want to follow your step. It would be great if you can list the product you used. I try to look for the fastener that attached form to masonry block but there no where to be found. I search the internet and I can't find the exact one you used. Thank you in advance.
How would you suggest I request our builder in upstate SC to do this if it isn't standard industry practice? 😅We haven't signed any contracts yet but I was told we will have to use a crawlspace instead of a slab and we're very concerned about mold growth to the point we may not move forward on the build because of it.
Sorry for the delay responding. Its a difficult question since most builders do not understand why a vented crawlspace has so many issues. You could try to have them understand the science behind an encapsulated crawlspace using resources such as crawlspaces.org. We would be happy to discuss this further with you if desired.
Great question Nick- Its not inexpensive. We were paying around $2.50 / SF of interior crawlspace until the recent supply chain challenges and price increases. Our cost now ranges from $3.10 - $3.95 / SF.
I have to ask on your reinforced vapor barrier are you not concerned at some point that it could separate and give off a bad odor such as a cat pee smell, there’s a contractor out of Knoxville Tennessee that does what you guys do and claims that reinforced vapor barriers can give off a cat pee like odor when they separate, have you experienced this?
We've been using this specific barrier for over 14 years and have never had any separation nor odor from the liner. It is a polyolefin polymer which is not reactive to most other materials (think milk jug).
You certainly could use closed cell on the walls and stop short of the top for the inspection gap. Most spray foam contractors will not come out for such a small job and it is more expensive than the foam board. Many spray foam formulations also require an ignition barrier to be applied too. One additional challenge of the spray foam is that many contractors spray the closed cell foam in the band of the floor system, which then makes it impossible to easily inspect the wood framing at the band for termites. We are in a high termite infestation zone, so we terminate our foam board 4 inches below the top of the foundation and use fiberglass batts at the band which can easily be removed for termite inspection. The exterior insulation on the outside of our homes extends down to the foundation, so the band also has an R-5 continuous thermal break on the outside.
@@toddusher2358 Thank you for your thorough explanation! I am in the process of designing our new home in Southern Georgia, and I want to use the pier and beam foundation design. I've researched it done 10,000 different ways it seems! I recently watched a Matt Risinger Pier and Beam build which is why I asked. Here is the video th-cam.com/video/yk0mchsMstQ/w-d-xo.html
@@NewVisionLCS No problem at all! I watched Matt's video and just a word of caution - the "pier and beam" foundation that he refers to is quite different than most "pier and beam" foundations here in the Southeast. Are you planning on using poured walls just as Matt did in his video? If so, no worries - just don't want you to get stuck with a local contractor misinterpreting what you mean by pier and beam. It differs even in parts of the Southeast, but in my area, most contractors refer to a pier and beam foundation as one with no perimeter curtain wall - they typically have only masonry or concrete piers with wood beams spanning between the piers, then a non-structural brick veneer around the perimeter. I would consider Matt's foundation to be a continuous concrete stemwall foundation with interior piers. Not trying to be a stickler, but it makes a difference depending on what part of the country you're in! If I can help with any ideas, please feel free to reach out!
@@toddusher2358 Yes, I want an exterior poured wall with interior piers, and I want it conditioned. No slab on grade for me! Have you guys built any homes in Southeast Georgia?
In many cases where the slope would work for a walk out basement, you are correct. For sites where a walk-out basement will not work or the client does not need the extra space of a basement, the encapsulated crawlspace still less expensive than a basement.
Just about to build a custom home for a client on a sandy island in Nova Scotia. Designing the crawlspaces has been a very important consideration, and your video has confirmed I’m on the right track! Thank you. I’ll be using StegoWrap and XPS foam, but a very similar group of materials.
ICFs are great but very expensive for a crawlspace foundation. If you were building a full ICF home, that would be a logical choice. The concrete slab in the crawlspace will require a vapor barrier beneath either way, so its just $$ to incorporate a concrete slab in the crawlspace. Always be sure to provide a 1-way crawlspace drain at the low point of the crawl foundation to allow water to escape if there is ever a plumbing leak beneath!
there is no need for a drain in a conditioned crawl space. a drain is only going to bring more moisture in and be an extra penetration that will add another moisture intrusion point
I’m trying to decide on whether to put the vapor barrier on top of the insulation foam or behind it. I noticed the majority of people put it on top of the insulation but some people like yourself go the other route. What’s the reasoning behind this and doesn’t even matter?
Its much easier to run the vapor barrier up behind the foam board and let the foam board "hold" the vapor barrier against the wall. My primary concern with installing the vapor barrier over the foam board would be moisture pickup in the foam from the ground layer below.
@@AddisonHomes thanks for the reply. I thought it through and decided the same. I put the vapor barrier behind the foam, but also decided to put another loose layer of vapor barrier on top of the foam because it’s more aesthetic and help protect foam from damage because I store things along the walls of my crawlspace
@Jan Toorop take it from a flooring specialist that has crawled into many nasty crawlspaces. Then you would understand and as a sidenote you breathe that air as well.
How does a sealed crawled space fare when the building is unoccupied, no power, between owners, hard times, etc. Should any crawl space retain the option of venting under such circumstances? If you've ever opened a cooler you haven't used in a while, even washed and in only a couple of days, you'll smell and probably see mold growth.
A conditioned, sealed crawl needs to be maintained within an acceptable humidity range either by operating the HVAC system or having a dedicated dehumidifier. It is not intended nor designed to be left unconditioned for any period of time. On the other hand, a vented crawl will always have a musty smell like a cooler due to high moisture and condensation on surfaces.
The first Concrete masonry units “cinder blocks” were developed in England in the 1850s and are used in many applications today ranging from foundations to commercial buildings. They have been used successfully in construction for over 100 years in the United States and are not “trash”. Settling of any foundation can potentially damage a building which is why it is of vital importance to ensure that the soil load bearing capacity is adequate for the building to be constructed, and the footings are designed and installed to be compatible with the soil bearing capacity and the building design (and include steel rebar reinforcement). If these components of a building’s foundation are not properly accounted for and designed, no foundation wall will be able to support the building successfully. Broad statements claiming certain building materials are “trash” without providing supporting data, are very misleading to those with limited knowledge of construction.
2 primary reasons in our market: 1) Cost and 2) Termites. To prevent moisture issues with spray foam in an encapsulated crawlspace, closed cell (2 lb) foam would be recommended. The vapor barrier would need to be extended up the lower portion of the foundation wall so that the foam can be sprayed on top to create a continuous barrier and a 4 inch termite inspection gap would have to be left at the top of the wall - same as with the foam board. The closed cell spray foam is much more expensive than the foam board, so it really doesn't make financial sense. We NEVER spray foam in the rim/band around the floor system in crawlspaces, as this prevents the termite inspector from easily inspecting for termites - the rim/band is where termites are often first discovered. Our termite service partner is ADAMANT that the rim/band is easily accessible for inspection, which for us means batt insulation on the interior and continuous insulation on the exterior.
Excellent video. Thanks Todd. Question: with a crawl space that deep (high), why not just make the walls a few feet higher and have a basement? Moisture potential? Expansive soils? Budget? Thanks - I'm considering options - crawl space or basement or slab first floor.
Fantastic question! The easiest (and often most cost effective) approach to foundations in the South that push 6-7 feet tall is to go all the way to a basement foundation and gain that space for future use. The encapsulated crawlspace is often the most expensive foundation type. The client on this particular project did not want the extra space of the basement (which would have added some incremental cost). So it was a decision based upon need and budget.
Watching again for the 10th time. I appreciate a video actually focused on climate zone 3 (I’m 3a hot humid but close enough). Couple questions come to mind. The exterior waterproofing- what is your cladding or are you backfilling that? The foam board- I presume that’s foil faced XPS? Thanks
So glad you’ve found it useful! The exterior foundation waterproofing will be covered by backfill. The foam board used on the interior foundation walls is foil faced polyiso foam.
Thanks. I saw in another comment where you had clarified also that the waterproofing was just up to the backfill level. I had assumed the was not polyiso since that is not rated for ground contact but, then again, this isn’t contacting the ground…that’s kind of the whole point. Thanks again.
May I ask why foam board and not just hiring a crew to spray foam over the vapor barrier? Is it to not have a delay between the crew who sprays the waterproofing and installs the vapor barrier? I would think a spray foam would be continuous.
One crew does waterproofing, liner, and foam board. Spray foam would add another crew and it is far more expensive. Many spray foam crews wouldn’t even touch only Crawlspace walls without a hefty minimum charge.
We are on the same page, one crew completes the job. I’ve just seen another builder in Kentucky do spray foam on the perimeter. I like your method, one crew and get it done.
What products would you suggest for a foundation like this? I see you have no vents in this wall. How are you going to remove humidity and bad air from the crawl space?
You can find all of the products at gmxwaterproofing.com The goal of a closed crawlspace is to seal it completely from the exterior. If the crawl is encapsulated properly, there is no bad air coming from the soil below and the humidity is controlled by a whole home dehumidifier.
My wife and I are in the process of building a new home in the Lancaster, SC area. Really enjoyed this presentation on conditioned crawl space construction. Who would I talk to at Addison Homes about working on a new construction home?
They should be listed in comments on this video but the spray on is a spray applied asphaltic emulsion used by many waterproofing companies.. The membrane is "BiLar" and can be found at www.gmxco.com
The waterproofing below grade with a perimeter drain is best practice for any Crawlspace or basement foundation to keep water out of the foundation. It’s not required by code for a Crawlspace, but without, you risk water issues, vented or not. The waterproofing we apply to the top of the foundation wall serves as a capillary break and is also simply a moisture management best practice to eliminate capillary moisture movement up through the foundation into the wood framing regardless of venting a Crawlspace or not.
Do you come back with a brick veneer on the exterior of the foundation to cover the black waterproofed CMU? I’ve noticed most crawls I’ve seen have 0 waterproofing, just the CMUs and raw dirt under the home and some don’t even put a capillary break. I can see what the plastic on the ground does to prevent ground moisture from rising and seems a very minimal cost increase to “sell” to a cost conscious home builder but what does waterproofing the CMUs do? I see you incorporated a capillary break with the waterproofing but want to understand the benefits of waterproofing the CMU. Thanks!
Hello! Great video. I am actually buying a house in a very close area from the video (Campobello). I am wondering if it is required for new homes to be build with a capillary break installed on the block these days? I know nothing of home building but know that the house I am trying to buy has a large crawlspace and know it has a dirt floor and a covering I assume (hoping) is a radon barrier.
Glad you enjoyed it! There is no code requirement for capillary break on foundation walls unfortunately. Current code does require a vapor barrier over the dirt in a crawlspace. This can reduce radon, IF there is a radon vent up through the roof.
We use the Hilti powder actuated gun with the foam fastener ram and the hilti foam fasteners. Simpson also makes a similar foam fastener for their regular gun I believe. The vendor, GMX supply also makes an adhesive that we use and works great. Its a polyurethane adhesive with good adhesive properties - Its called SealIt XP. www.gmxco.com/products/crawl-space-systems.html
Its a combination of our rolling topography and relatively high frost line that resulted in crawlspace foundations historically. They still make sense when a lot has some slope but a basement isn't needed by the homeowner. But your observation is on target - if another foundation type (slab or basement) can be justified, it makes far more sense!!!
Hi Cindi- The good thing is that the foundation wall is not sealed on all sides so moisture can always migrate up the wall and to the exterior of the foundation above the exterior waterproofing. The key goal is to prevent moisture from coming into the sealed crawlspace or up into the wood framing. Giving moisture this path to migrate outward of the house is perfect - allowing it to move without coming into the house area.
@@AddisonHomes I'm not understanding... the exterior waterproofing goes all the way up the exterior and over the top. Where can it escape? (You said above the waterproofing, but it looks like only framing is above the waterproofing.) Also can you explain why you installed a sacrificial vapor barrier instead of just installing the good one from the start? If it's super tough and would also keep moisture out?
@@cindianderson9443 Thanks for the clarification questions. We do not run the waterproofing all the way up the exterior of the foundation wall. We only waterproof up to the height where final grade will be around the exterior of the foundation. The foundation wall above final grade is not waterproofed - By code, there must be at least 6 inches of foundation between grade and siding/framing - the only exception to this is in our zero step garages. Sacrificial vapor barrier is exactly that - sacrificial. Even the most robust vapor barrier would be completely abused during construction and would be in no condition to leave as the final barrier for an encapsulated crawlspace. With the red clay in our region, the white heavy duty membrane would be red with mud!
@@AddisonHomes Thanks, that's interesting. I'm used to people putting self-adhered or fluid applied membrane over the whole outside foundation wall, then overlapping the house membrane to that one. But not putting any on top or on the inside. (Usually use other things like sill seal on top.) Lots of different approaches.
Good info Cindy but I’m still unclear on the moisture barrier explanation. In the video I see them spraying from bottom to the top of the wall. Not sure where you have four inches of untreated block to allow moisture to escape . No matter where the grade is the wall is sealed. Please clarify. Thx
Great presentation. I had not considered a need to vent a crawlspace during construction, but until it is "conditioned" it really does make sense. I like the moisture sensor and the one-way drain, too. Seems like a lot of steps and different materials to isolate the masonry from the framing, though. I always worry when I see a bunch of penetrations being made by fasteners through vapor barriers. It seems like it would be simpler to wrap both sides of the masonry wall with your vapor barrier so it covers the top to provide your capillary break. Why is the black spray better ? On the outside, the vapor barrier could hang down to the footer and be held in place behind insulation board by backfill with no penetrations. On the inside it could be taped to the floor covering. When the framed walls are sheathed, the house wrap or self adhesive membrane vapor retarder could shingle over from the sheathing onto the stem wall and be taped to the VB. Continuous R13 insulation board covering the sheathing could run down over the sheathed wall and stem wall all the way to the footer. That would mean the rim joist and framing inside would be visible for termite inspection without leaving the gap in the foam board as a thermal bridge. The vapor barrier in the crawlspace would be a continuous barrier isolating all the masonry and earth from the wood framing. Will termites penetrate that tough VB you used ? Seems like less labor overall than all the fastening and calking of the VB and foam board while leaving fewer gaps in the insulation. Bringing the stem wall inside the conditioned space would add thermal mass.
Thanks for the comments. Interesting idea to wrap the wall with the vapor barrier. In practice, this would be very difficult to get the vapor barrier of this thickness to "hug" the wall without fasteners. The requirement to have a positive connection between the foundation and the framing would require penetrations through the vapor barrier which could be problematic from a moisture and termite perspective. I wouldn't rely on the vapor barrier with penetrations as an adequate capillary break. Depending on the type of continuous insulation board, if it ran from the exterior framed wall down over the foundation wall to the footer, this would provide a path for termites to move from below grade up the outside of the wall into the framing unnoticed. Of course, termite flashing could be installed at a break in the foam to reduce the chance of this from happening. Another drawback of continuous insulation on the exterior of the foundation is the final exterior finish. The exterior insulation would need to be protected from damage. A common finish over foam board would be synthetic stucco, but it would still be susceptible to damage from string trimmers and other landscaping equipment or activities. Overall, I think the cost and complexity of this approach would be prohibitive. One other option for the membrane would be to wrap the wall with a peel and stick membrane which would eliminate fasteners, but would not address the issue of the foundation connection to framing. This would also be extremely costly. Again - thanks for the comments and ideas. I always enjoy discussing different construction assemblies. Innovation is very important in our industry!
@@AddisonHomes Thanks for the quick reply. I think a peel and Stick membrane would gasket over the J bolts or other foundation connectors. To be sure there wasn't a gap between masonry and sill plate, I suppose you would need a thicker gasket material than just the VB anyway. I was thinking the weight of the gravel for the exterior drain sitting on top of the VB draped over the outside and down onto the footer would pull it tight to hug the exterior wall, then the insulation board would hold it against the wall by the pressure of the backfill the way they do a permanent wood foundation. But not in practice ? Is hugging the wall on the interior important ? I know termites and carpenter ants will tunnel through foam and is one reason I don't like the idea of foam outside at all. What do you think of the Rockwool Board material for exterior insulation and termites ? It doesn't hold water, and termites don't tunnel through it, do they ? You treat the wood within 4' of the piers with boric acid, but not the wood wall framing ? Just the sill plate ? Termites are a big problem in California where I want to build, but I haven't seen this level of precaution out here. I wish it were practical to end up with a box completely wrapped in bug and moisture proof barrier, with all continuous exterior insulation like REMOTE, then control ventilation and humidity with HRV and dehumidifier. Out here, they put continuous VB under slabs but don't then wrap it up the outside of slab onto and under the sill plate. So the concrete is not really isolated from the ground and weather and I've never understood why. Seems like that would work for crawlspace foundations, too, with the VB under all the footings and piers continuous. On a non-VB note, some builders use additional strip footings and short walls rather than piers and beams. Do you prefer pier and beam because it keeps the wood further from the ground for termite reasons, or something else ? Why not short steel adjustable columns instead of concrete piers ? A crawlspace is just a short basement, isn't it ?
lets not talk about the fact that every single fastener he used is a potential source of moisture intrusion. not only are there fasteners in the membrane but then more fasteners in the foam board. much better to use special adhesives designed for this application.
Not really - the foundation wall is waterproofed on the exterior and the fasteners are only on the interior side of the 8" thick wall. They penetrate no more than 1/2". We are not relying on the membrane nor the foam board to be moisture barriers on the interior of the foundation wall.
Excellent job on the video. You deserve a bigger following! I am also in Upstate SC. Currently getting ready to build two houses on twenty acres my son and I are developing for a small homestead for our families. We are doing a very similar crawl space. This is very helpful!! I like the idea of sealing the top of the wall against moisture. So many people feel I am waisting my time doing all this extra work. To me its just part of what needs to be done especially in our humid climate. I have been an electrical contractor and in construction most of my life. You doing this to your foundation tells me your top notch and its highly likely every aspect of your homes is top notch as well. Wish more people cared about the details.
You get an A+++!!!
Terry
Thanks so much Terry! Glad the videos are helpful! That's our goal!!! Like and share us to help get the word out. More education is needed in the industry. Sounds like you're doing it the right way and it will pay huge dividends over your lifetime in the house and the life of the home! We run into folks who think its a waste of time frequently but the awareness is building and more folks understand why building better on the most expensive investment most of us make is a very smart decision! Once people have lived in a better built home, they are completely sold on the results. If we can help with suggestions on your build, don't hesitate to reach out!
That is so true! Our founder enclosed his first crawlspace on his 1970's built home 18 years ago and learned first hand how beneficial encapsulated crawlspaces are as well and how difficult encapsulating after the fact is!
So glad to have you follow us! We’ve known Matt for years and, like he and the build show team, we enjoy sharing our experiences with the world in hopes that it’s helpful for folks and provides a better understanding on east ways to build better!
If you’re ever back in SC, reach out!
Took me weeks to do this after the house was already built. This is way smarter to do it at this phase.
Agreed! We have done it both ways and learned!
Hey just discovered your channel (I'm a Build Show/Matt Risinger watcher). This summer we vacationed at Lake Keowee, really cool place!
Fantastic! Glad to have you following. Matt does a great job and we are trying to fill in some of the gaps unique to the Southeast.
Great video. When connecting and taping the vertical and horizontal sheets of plastic film which one do you overlap on top of the other?
Great question! I always use the “think like a shingle” mantra which you have to think about upside down since we are concerned about potential water from underneath. So, the membrane on the floor is lapped on top of the membrane coming down the foundation walls. Laps on the floor membrane will depend on the slope of the Crawlspace floor. If water were to flow beneath the membrane, we want to avoid water “catching” a lap from beneath bringing the water to the tape seam above. Let us know if this makes sense. If it doesn’t, we can make a quick video to illustrate.
Outstanding video (my lot is amazingly similar with lake view to yours here) - I am in Climate Zone 4 in Northwest Arkansas, nearly Zone 3. I'll preference my three questions with, I am not a builder: 1) Why do most of your sill plate bolts appear bent, or is that tape covering them, and 2) Will you be installing a termite shield? 3) What is the waterproofing liquid being used and is it just a standard product? Thanks - my new home foundation is going in now and I am having a heck of a time communicating to my builder to do similar to your installation here in my crawl. I need to get to some agreement with him before he gets to the sill plate.
1) I think you're seeing our foundation "straps" which we use instead of bolts. These are embedded in the foundation and bent around the framing and nailed to the framing in multiple holes. We find that the straps can not only hold the sill plate, but run up the wall and attach to framing as well.
2) We install termite shielding on our insulated stemwall slab foundations which we will be discussing in some upcoming videos, but do not install specific termite shields on our crawlspace foundations. We treat all of our homes with borate termite treatment applied to the wood framing 3 feet in all directions from any contact with masonry or concrete.
3) The waterproofing is a standard asphalt-type emulsion.
Outstanding video. Can you please share what you used for the waterproofing spray-on liquid?
Check out the products at GMXCO.com
Is there a reason NOT to pour concrete for the crawlspace floor? I mean other than cost, obviously. I'm adding a 900 SF rectangular addition to my home. I think I would like a full concrete floorspace with about a 4-5 foot depth. I mostly want sealed environment storage. Am I wasting money? Is your system a better way? I watched the other video with the finished-out area and it does look great.
Great question. It definitely an option for an encapsulated Crawlspace. Just need to insure that the vapor barrier is continuous under the concrete and sealed to the foundation walls. The concrete is more expensive but makes for a super nice space! You can actually pour a thinner slab (2-3” vs 4”) since it’s not going to have heavy traffic. Please send pictures if you pour it!!
So, for encapsulated crawlspace, built from the beginning as such, you wouldn't just build it the way a pool is made? I was watching video I took of the construction of my pool. They dug the hole with a skid steer. Put down rock. Compacted it. The put rebar down the sides and across the middle. One giant wire mesh everywhere. Then they started blowing concrete. No barriers! Is that because you dont care about moisture with a pool? Lol
@@AddisonHomes
Thank you for responding. I'm exploring all my options and this is very helpful.
@addisonhomes Also, could you use galvanized steel posts instead of concrete & rebar columns? You know, like they have in a warehouse to hold up the steel beam ceilings.
@@4813RT would just be an expensive Crawlspace!
Why is there no termite inspection gap in a finished basement?
When are we going to get the codes updated for a crawlspace built to this level.
Seems like a gap is not needed if the inside of the crawl space is going to be built that well.
Next question why not water proof under the footing to stop moisture flow from the bottom instead of letting g it wick all the way up the block wall?
Great questions:
- The termite inspection gap is impractical on a finished basement since it is typically inaccessible when a drywall ceiling is used. For a lay-in tile ceiling, the top of the wall is accessible for inspection.
- The gap is needed for a close crawlspace. Without the gap, there would be no way to see if termites were tunneling up through the foam insulation board.
- Waterproofing under the footing is more challenging than it sounds. In the Southeast, we typically dig a footing trench and fill it with concrete. In order to waterproof the footing, we would need to line the trench with a moisture barrier and ensure it gets wrapped around the footing. Realistically, it is difficult to ensure that this barrier is 100% and also difficult to ensure that rain/moisture doesn't soak into the masonry wall above the waterproofing and wick up to the framing.
We have found that the spray applied sealant is extremely easy to apply to the top of the wall while our waterproofing contractor is on-site spraying the exterior below grade foundation walls.
There is a product that @jake.bruton.arrow.building covered in a recent video that is actually a footing form that potentially doubles as a waterproofing footing wrap.
Love your video. Im a new builder and want to follow your step. It would be great if you can list the product you used. I try to look for the fastener that attached form to masonry block but there no where to be found. I search the internet and I can't find the exact one you used. Thank you in advance.
This is a pretty common foam fastener for powder actuated fastening guns. A google search brings up several.
How would you suggest I request our builder in upstate SC to do this if it isn't standard industry practice? 😅We haven't signed any contracts yet but I was told we will have to use a crawlspace instead of a slab and we're very concerned about mold growth to the point we may not move forward on the build because of it.
Sorry for the delay responding. Its a difficult question since most builders do not understand why a vented crawlspace has so many issues. You could try to have them understand the science behind an encapsulated crawlspace using resources such as crawlspaces.org. We would be happy to discuss this further with you if desired.
@@AddisonHomes thank you! We were actually able to find a lot that they could build on slab instead do we went with that!
Curious, what is an averange price range per square foot for a crawlspace like this?
Great question Nick- Its not inexpensive. We were paying around $2.50 / SF of interior crawlspace until the recent supply chain challenges and price increases. Our cost now ranges from $3.10 - $3.95 / SF.
@@AddisonHomes what about issues described in this video? th-cam.com/video/pgA7FqD2IR8/w-d-xo.html
ICF with a concrete floor crawl space would be better to seal in the area no?
I'm always concerned with termite issues with ICFs in contact with the ground in our high termite area.
I have to ask on your reinforced vapor barrier are you not concerned at some point that it could separate and give off a bad odor such as a cat pee smell, there’s a contractor out of Knoxville Tennessee that does what you guys do and claims that reinforced vapor barriers can give off a cat pee like odor when they separate, have you experienced this?
We've been using this specific barrier for over 14 years and have never had any separation nor odor from the liner. It is a polyolefin polymer which is not reactive to most other materials (think milk jug).
@@michelleusher2355 can the general public purchase this product?
Not talking about crawl space ninja at all.
@@AddisonHomes that would be him yes , he of course I don’t have to tell you that he’s all over TH-cam
@@Bossman_71 I'm not familiar wtih him.
I'm ready to build my house. Don't if I want crawl space or concrete slab
Let us know if we can help in any way!
Why not just use closed cell spray foam instead of styrofoam board?
You certainly could use closed cell on the walls and stop short of the top for the inspection gap. Most spray foam contractors will not come out for such a small job and it is more expensive than the foam board. Many spray foam formulations also require an ignition barrier to be applied too. One additional challenge of the spray foam is that many contractors spray the closed cell foam in the band of the floor system, which then makes it impossible to easily inspect the wood framing at the band for termites. We are in a high termite infestation zone, so we terminate our foam board 4 inches below the top of the foundation and use fiberglass batts at the band which can easily be removed for termite inspection. The exterior insulation on the outside of our homes extends down to the foundation, so the band also has an R-5 continuous thermal break on the outside.
@@toddusher2358 Thank you for your thorough explanation! I am in the process of designing our new home in Southern Georgia, and I want to use the pier and beam foundation design. I've researched it done 10,000 different ways it seems! I recently watched a Matt Risinger Pier and Beam build which is why I asked. Here is the video
th-cam.com/video/yk0mchsMstQ/w-d-xo.html
@@NewVisionLCS No problem at all! I watched Matt's video and just a word of caution - the "pier and beam" foundation that he refers to is quite different than most "pier and beam" foundations here in the Southeast. Are you planning on using poured walls just as Matt did in his video? If so, no worries - just don't want you to get stuck with a local contractor misinterpreting what you mean by pier and beam. It differs even in parts of the Southeast, but in my area, most contractors refer to a pier and beam foundation as one with no perimeter curtain wall - they typically have only masonry or concrete piers with wood beams spanning between the piers, then a non-structural brick veneer around the perimeter. I would consider Matt's foundation to be a continuous concrete stemwall foundation with interior piers.
Not trying to be a stickler, but it makes a difference depending on what part of the country you're in! If I can help with any ideas, please feel free to reach out!
@@toddusher2358 Yes, I want an exterior poured wall with interior piers, and I want it conditioned. No slab on grade for me! Have you guys built any homes in Southeast Georgia?
The money you spend on all this you could have had a basement.
In many cases where the slope would work for a walk out basement, you are correct. For sites where a walk-out basement will not work or the client does not need the extra space of a basement, the encapsulated crawlspace still less expensive than a basement.
Just about to build a custom home for a client on a sandy island in Nova Scotia. Designing the crawlspaces has been a very important consideration, and your video has confirmed I’m on the right track! Thank you.
I’ll be using StegoWrap and XPS foam, but a very similar group of materials.
ICFs are great but very expensive for a crawlspace foundation. If you were building a full ICF home, that would be a logical choice. The concrete slab in the crawlspace will require a vapor barrier beneath either way, so its just $$ to incorporate a concrete slab in the crawlspace. Always be sure to provide a 1-way crawlspace drain at the low point of the crawl foundation to allow water to escape if there is ever a plumbing leak beneath!
Where's the ICF?
Insulated Concrete Form
there is no need for a drain in a conditioned crawl space. a drain is only going to bring more moisture in and be an extra penetration that will add another moisture intrusion point
I’m trying to decide on whether to put the vapor barrier on top of the insulation foam or behind it. I noticed the majority of people put it on top of the insulation but some people like yourself go the other route. What’s the reasoning behind this and doesn’t even matter?
Its much easier to run the vapor barrier up behind the foam board and let the foam board "hold" the vapor barrier against the wall. My primary concern with installing the vapor barrier over the foam board would be moisture pickup in the foam from the ground layer below.
@@AddisonHomes thanks for the reply. I thought it through and decided the same. I put the vapor barrier behind the foam, but also decided to put another loose layer of vapor barrier on top of the foam because it’s more aesthetic and help protect foam from damage because I store things along the walls of my crawlspace
Does pouring a slab in the crawl control moisture?
Great question - not without a moisture barrier beneath the slab.
Vented crawlspace is the worst building mistake made in the last 100 years or more
@Jan Toorop take it from a flooring specialist that has crawled into many nasty crawlspaces. Then you would understand and as a sidenote you breathe that air as well.
So true!!!
How does a sealed crawled space fare when the building is unoccupied, no power, between owners, hard times, etc. Should any crawl space retain the option of venting under such circumstances? If you've ever opened a cooler you haven't used in a while, even washed and in only a couple of days, you'll smell and probably see mold growth.
A conditioned, sealed crawl needs to be maintained within an acceptable humidity range either by operating the HVAC system or having a dedicated dehumidifier. It is not intended nor designed to be left unconditioned for any period of time. On the other hand, a vented crawl will always have a musty smell like a cooler due to high moisture and condensation on surfaces.
Any kind of settling of the wall will destroy that home. Cinder blocks are trash.
The first Concrete masonry units “cinder blocks” were developed in England in the 1850s and are used in many applications today ranging from foundations to commercial buildings. They have been used successfully in construction for over 100 years in the United States and are not “trash”. Settling of any foundation can potentially damage a building which is why it is of vital importance to ensure that the soil load bearing capacity is adequate for the building to be constructed, and the footings are designed and installed to be compatible with the soil bearing capacity and the building design (and include steel rebar reinforcement). If these components of a building’s foundation are not properly accounted for and designed, no foundation wall will be able to support the building successfully.
Broad statements claiming certain building materials are “trash” without providing supporting data, are very misleading to those with limited knowledge of construction.
Were do you get enclosement material that goes over the foam board? Great Video also.
@@jims3650 thanks! Try gmxco.com
Why not just spray the crawl space walls with spray foam insulation? Seems like a way better way to do it .
2 primary reasons in our market: 1) Cost and 2) Termites. To prevent moisture issues with spray foam in an encapsulated crawlspace, closed cell (2 lb) foam would be recommended. The vapor barrier would need to be extended up the lower portion of the foundation wall so that the foam can be sprayed on top to create a continuous barrier and a 4 inch termite inspection gap would have to be left at the top of the wall - same as with the foam board. The closed cell spray foam is much more expensive than the foam board, so it really doesn't make financial sense. We NEVER spray foam in the rim/band around the floor system in crawlspaces, as this prevents the termite inspector from easily inspecting for termites - the rim/band is where termites are often first discovered. Our termite service partner is ADAMANT that the rim/band is easily accessible for inspection, which for us means batt insulation on the interior and continuous insulation on the exterior.
Excellent video. Thanks Todd. Question: with a crawl space that deep (high), why not just make the walls a few feet higher and have a basement? Moisture potential? Expansive soils? Budget? Thanks - I'm considering options - crawl space or basement or slab first floor.
Fantastic question! The easiest (and often most cost effective) approach to foundations in the South that push 6-7 feet tall is to go all the way to a basement foundation and gain that space for future use. The encapsulated crawlspace is often the most expensive foundation type. The client on this particular project did not want the extra space of the basement (which would have added some incremental cost). So it was a decision based upon need and budget.
@@AddisonHomes Makes sense. Thank you.
Watching again for the 10th time. I appreciate a video actually focused on climate zone 3 (I’m 3a hot humid but close enough). Couple questions come to mind.
The exterior waterproofing- what is your cladding or are you backfilling that?
The foam board- I presume that’s foil faced XPS?
Thanks
So glad you’ve found it useful! The exterior foundation waterproofing will be covered by backfill. The foam board used on the interior foundation walls is foil faced polyiso foam.
Thanks. I saw in another comment where you had clarified also that the waterproofing was just up to the backfill level.
I had assumed the was not polyiso since that is not rated for ground contact but, then again, this isn’t contacting the ground…that’s kind of the whole point.
Thanks again.
May I ask why foam board and not just hiring a crew to spray foam over the vapor barrier? Is it to not have a delay between the crew who sprays the waterproofing and installs the vapor barrier?
I would think a spray foam would be continuous.
One crew does waterproofing, liner, and foam board. Spray foam would add another crew and it is far more expensive. Many spray foam crews wouldn’t even touch only Crawlspace walls without a hefty minimum charge.
We are on the same page, one crew completes the job. I’ve just seen another builder in Kentucky do spray foam on the perimeter.
I like your method, one crew and get it done.
If I may ask, sir... What product are you utilizing for your spray waterproofing membrane and capillary break? Thanks in advance.
I'm not sure of the specific name, but it is foil faced and passes the code requirements for exposed installation in crawlspaces/basements.
Why crawlspace instead of slab or basement?
Heavy rain, flooding(raises your home). Plumbing, electrical, hvac, etc is accessible. So, you don't have to break up concrete.
This project could have easily been a walk-out/daylight basement but the homeowner didn't want a basement. Topography had too much slope for a slab.
Name of the membrane pls 😬😬😬😬
Bi-Lar. Its in prior comments along with the website.
What products would you suggest for a foundation like this? I see you have no vents in this wall. How are you going to remove humidity and bad air from the crawl space?
You can find all of the products at gmxwaterproofing.com The goal of a closed crawlspace is to seal it completely from the exterior. If the crawl is encapsulated properly, there is no bad air coming from the soil below and the humidity is controlled by a whole home dehumidifier.
Loved this video. I'd love to know where you source the vapor barrier membrane and the sealant caulk you use.
Try GMXCO.com
Great video What's the name of the membrane product shown in your video thanks
BiLar
My wife and I are in the process of building a new home in the Lancaster, SC area. Really enjoyed this presentation on conditioned crawl space construction. Who would I talk to at Addison Homes about working on a new construction home?
We don't currently build in the Lancaster area, but would be happy to speak with you about your project to offer any advice.
what's the spray on membrane and what is the material membrane you tried to rip? please and thank you
They should be listed in comments on this video but the spray on is a spray applied asphaltic emulsion used by many waterproofing companies.. The membrane is "BiLar" and can be found at www.gmxco.com
What is the name of the John mansville insulation that you used? Beautiful job thanks Vince
Johns Manville CI Max
So if doing a vented crawl, will the black waterproofing paint be needed? If so, what does it do, the purpose?
The waterproofing below grade with a perimeter drain is best practice for any Crawlspace or basement foundation to keep water out of the foundation. It’s not required by code for a Crawlspace, but without, you risk water issues, vented or not. The waterproofing we apply to the top of the foundation wall serves as a capillary break and is also simply a moisture management best practice to eliminate capillary moisture movement up through the foundation into the wood framing regardless of venting a Crawlspace or not.
Do you come back with a brick veneer on the exterior of the foundation to cover the black waterproofed CMU?
I’ve noticed most crawls I’ve seen have 0 waterproofing, just the CMUs and raw dirt under the home and some don’t even put a capillary break.
I can see what the plastic on the ground does to prevent ground moisture from rising and seems a very minimal cost increase to “sell” to a cost conscious home builder but what does waterproofing the CMUs do? I see you incorporated a capillary break with the waterproofing but want to understand the benefits of waterproofing the CMU.
Thanks!
Hello! Great video. I am actually buying a house in a very close area from the video (Campobello). I am wondering if it is required for new homes to be build with a capillary break installed on the block these days? I know nothing of home building but know that the house I am trying to buy has a large crawlspace and know it has a dirt floor and a covering I assume (hoping) is a radon barrier.
Glad you enjoyed it! There is no code requirement for capillary break on foundation walls unfortunately. Current code does require a vapor barrier over the dirt in a crawlspace. This can reduce radon, IF there is a radon vent up through the roof.
@@AddisonHomes Thank you for the quick reply! Cheers!
Which gun, fasteners, and adhesive are you using?
We use the Hilti powder actuated gun with the foam fastener ram and the hilti foam fasteners. Simpson also makes a similar foam fastener for their regular gun I believe. The vendor, GMX supply also makes an adhesive that we use and works great. Its a polyurethane adhesive with good adhesive properties - Its called SealIt XP. www.gmxco.com/products/crawl-space-systems.html
Seems silly to build a useless crawlspace and not a basement.
Is it just tradition down there?
Its a combination of our rolling topography and relatively high frost line that resulted in crawlspace foundations historically. They still make sense when a lot has some slope but a basement isn't needed by the homeowner. But your observation is on target - if another foundation type (slab or basement) can be justified, it makes far more sense!!!
We considered a basement but it would have added a significant increase in our school fees per square foot. Which our tight budget couldn't afford.
Rock is a factor and older people don’t won’t basement, due to stairs and cost.
What brand is that membrane?
BiLar
I'm scratching my head on this one, whether we really want that wall sealed on all sides... I personally never like to trap moisture.
Hi Cindi- The good thing is that the foundation wall is not sealed on all sides so moisture can always migrate up the wall and to the exterior of the foundation above the exterior waterproofing. The key goal is to prevent moisture from coming into the sealed crawlspace or up into the wood framing. Giving moisture this path to migrate outward of the house is perfect - allowing it to move without coming into the house area.
@@AddisonHomes I'm not understanding... the exterior waterproofing goes all the way up the exterior and over the top. Where can it escape? (You said above the waterproofing, but it looks like only framing is above the waterproofing.)
Also can you explain why you installed a sacrificial vapor barrier instead of just installing the good one from the start? If it's super tough and would also keep moisture out?
@@cindianderson9443 Thanks for the clarification questions. We do not run the waterproofing all the way up the exterior of the foundation wall. We only waterproof up to the height where final grade will be around the exterior of the foundation. The foundation wall above final grade is not waterproofed - By code, there must be at least 6 inches of foundation between grade and siding/framing - the only exception to this is in our zero step garages.
Sacrificial vapor barrier is exactly that - sacrificial. Even the most robust vapor barrier would be completely abused during construction and would be in no condition to leave as the final barrier for an encapsulated crawlspace. With the red clay in our region, the white heavy duty membrane would be red with mud!
@@AddisonHomes Thanks, that's interesting. I'm used to people putting self-adhered or fluid applied membrane over the whole outside foundation wall, then overlapping the house membrane to that one. But not putting any on top or on the inside. (Usually use other things like sill seal on top.) Lots of different approaches.
Good info Cindy but I’m still unclear on the moisture barrier explanation. In the video I see them spraying from bottom to the top of the wall. Not sure where you have four inches of untreated block to allow moisture to escape . No matter where the grade is the wall is sealed. Please clarify. Thx
Great presentation. I had not considered a need to vent a crawlspace during construction, but until it is "conditioned" it really does make sense. I like the moisture sensor and the one-way drain, too. Seems like a lot of steps and different materials to isolate the masonry from the framing, though.
I always worry when I see a bunch of penetrations being made by fasteners through vapor barriers. It seems like it would be simpler to wrap both sides of the masonry wall with your vapor barrier so it covers the top to provide your capillary break. Why is the black spray better ? On the outside, the vapor barrier could hang down to the footer and be held in place behind insulation board by backfill with no penetrations. On the inside it could be taped to the floor covering. When the framed walls are sheathed, the house wrap or self adhesive membrane vapor retarder could shingle over from the sheathing onto the stem wall and be taped to the VB. Continuous R13 insulation board covering the sheathing could run down over the sheathed wall and stem wall all the way to the footer. That would mean the rim joist and framing inside would be visible for termite inspection without leaving the gap in the foam board as a thermal bridge. The vapor barrier in the crawlspace would be a continuous barrier isolating all the masonry and earth from the wood framing. Will termites penetrate that tough VB you used ? Seems like less labor overall than all the fastening and calking of the VB and foam board while leaving fewer gaps in the insulation. Bringing the stem wall inside the conditioned space would add thermal mass.
Thanks for the comments. Interesting idea to wrap the wall with the vapor barrier. In practice, this would be very difficult to get the vapor barrier of this thickness to "hug" the wall without fasteners. The requirement to have a positive connection between the foundation and the framing would require penetrations through the vapor barrier which could be problematic from a moisture and termite perspective. I wouldn't rely on the vapor barrier with penetrations as an adequate capillary break.
Depending on the type of continuous insulation board, if it ran from the exterior framed wall down over the foundation wall to the footer, this would provide a path for termites to move from below grade up the outside of the wall into the framing unnoticed. Of course, termite flashing could be installed at a break in the foam to reduce the chance of this from happening.
Another drawback of continuous insulation on the exterior of the foundation is the final exterior finish. The exterior insulation would need to be protected from damage. A common finish over foam board would be synthetic stucco, but it would still be susceptible to damage from string trimmers and other landscaping equipment or activities.
Overall, I think the cost and complexity of this approach would be prohibitive.
One other option for the membrane would be to wrap the wall with a peel and stick membrane which would eliminate fasteners, but would not address the issue of the foundation connection to framing. This would also be extremely costly.
Again - thanks for the comments and ideas. I always enjoy discussing different construction assemblies. Innovation is very important in our industry!
@@AddisonHomes Thanks for the quick reply. I think a peel and Stick membrane would gasket over the J bolts or other foundation connectors. To be sure there wasn't a gap between masonry and sill plate, I suppose you would need a thicker gasket material than just the VB anyway. I was thinking the weight of the gravel for the exterior drain sitting on top of the VB draped over the outside and down onto the footer would pull it tight to hug the exterior wall, then the insulation board would hold it against the wall by the pressure of the backfill the way they do a permanent wood foundation. But not in practice ? Is hugging the wall on the interior important ? I know termites and carpenter ants will tunnel through foam and is one reason I don't like the idea of foam outside at all. What do you think of the Rockwool Board material for exterior insulation and termites ? It doesn't hold water, and termites don't tunnel through it, do they ? You treat the wood within 4' of the piers with boric acid, but not the wood wall framing ? Just the sill plate ? Termites are a big problem in California where I want to build, but I haven't seen this level of precaution out here. I wish it were practical to end up with a box completely wrapped in bug and moisture proof barrier, with all continuous exterior insulation like REMOTE, then control ventilation and humidity with HRV and dehumidifier. Out here, they put continuous VB under slabs but don't then wrap it up the outside of slab onto and under the sill plate. So the concrete is not really isolated from the ground and weather and I've never understood why. Seems like that would work for crawlspace foundations, too, with the VB under all the footings and piers continuous.
On a non-VB note, some builders use additional strip footings and short walls rather than piers and beams. Do you prefer pier and beam because it keeps the wood further from the ground for termite reasons, or something else ? Why not short steel adjustable columns instead of concrete piers ? A crawlspace is just a short basement, isn't it ?
lets not talk about the fact that every single fastener he used is a potential source of moisture intrusion. not only are there fasteners in the membrane but then more fasteners in the foam board. much better to use special adhesives designed for this application.
Not really - the foundation wall is waterproofed on the exterior and the fasteners are only on the interior side of the 8" thick wall. They penetrate no more than 1/2". We are not relying on the membrane nor the foam board to be moisture barriers on the interior of the foundation wall.