Helpful information. It's nice having an airtight home. On the flip side if moisture ever gets in your walls you've effectively sealed off one of its primary exits. I guess if you're going for airtight, you should also go the extra mile to make sure that moisture never gets in, if it does, it's going to do more damage and the repairs will be costlier.
Yes because old houses never have rot or mold problems. Their ability to "breathe" with massive air leaks always comes to the rescue without any downsides whatsoever.
Matt's videos have been very helpful as I bridge the gap between commercial and residential construction. Using the primed tapes to seal from the sheathing to the foundation is essentially a lighter version of what we recommend in the commercial world. As long as there are no large gaps between the two substrates and as long as the surfaces of the foundation aren't soiled, I'm in complete agreement with this approach. But, sealing from the inside - whether with caulk or tape - isn't air sealing at all. Because of the seam between the sheathing and the bottom plate, air barrier continuity is broken where the sheathing meets the foundation wall. If you're not sealing the sheathing-to-foundation interface from the outside, in my opinion you're not air sealing. You're probably not bug sealing very well either.
Sealing the framing/concrete joint also has the benefit keeping the bugs out. It sounds like the tape, properly applied, would work great but I'd also caulk the joint as a backup. It's cheap and doesn't take long to lay a bead around the building perimeter. How do you conceal the tape on the concrete? Does the siding hang down a few inches???
Hi Matt! Thanks so much for sharing your expertise with such clarity and great presentation! I have a huge problem. My brick ledge is only three inches. No room for exterior insulation 😢I need to extend my brick ledge. Any suggestions? Please! It’s getting cold here in Michigan. Thanks again
Matt, the building trade needs to 'take in' and accept your views. What you are preaching is very important, it needs more publicity, the law behind it, and promoting. Thank you. A Limey from you can guess where?
I've watched several videos that Matt has made concerning sill plate sealing. He has promoted several different products, from a foam strip, to a neoprene strip, to an accoustic caulk. Which is best???
Matt, when sheathing - is it best to flush the outside of the slab with the outside of the sheathing? And install bottom plate 1/2" inside of the slab? For ease of air seal taping... Or, install sheathing so it overlaps the slab? Ansd then dealing with the 'step' under the sheathing edge? ..In each case, raise the sheathing up by 1/8 up 'n off the slab? What's optimal?
I personally think both would work fine so long as you fluid apply when you in set it 1/2 inch. I would give it more like 1/4 gap. Concrere can release moisture I wouldn't want to trap it in there only using a tape. Personally I don't see any benefits from in setting it 1/2 anyway though. It might make it easier to straiten the mudsill I suppose.
The answer is to use more Polyester Breathable Fabrics everywhere, 100% airtight homes are not possible, but breathable and increased airtightness are, I have argued for years the top plate must be sealed, in fact all homes must be made weatheright and air tight, and this is where Dupont USA should lead and educate us all. One day all good homes will be TYVEK WRAPPED homes, not just a few, but 100% of all new builds.
When sealing the outside, how does one handle lapping of the tape? Best practices for window detailing might lap housewrap (or similar) over the top of sealing tape. (I've repeatedly heard "Think like a raindrop, act like a leaf" at green building seminars.) However, as shown in the video, any failure of the adhesive might route moisture onto the sill plate. Also, there are regions of the US that must deal with termites. It seems like the sealing tape might have a secondary benefit there, but it would be illuminating to hear how detailing might change to accommodate this application. Thanks!
I’m not a builder so don’t take my opinion too seriously. He tends to use the zip system so there is no house wrap. It’s built into the sheathing. I imagine if you have a very low window close to the foundation, you would use the siga tape first. Then use the zip stretch flashing at the bottom of the window so it overlaps the siga tape. I guess if you are really concerned about the siga tape peeling at the top and becoming a water trap, i guess you could go over the edges with something like the zip system liquid flash. It’s the same stuff that’s used to seal all the other openings for pipes and stuff.
We use Tamlyn products with Hardie panel and lap siding; how would those products be installed to hide the tape at the foundation wall. Tamlyn sections show the product flush with bottom plate and sheathing, not overhanging it. Do your siding projects ever encounter this detail? Appreciate your content, as always.
As a carpenter for forty years if I saw this type of air sealing done to my framing job I'd be sick my job had this mess all over it...same with walls! Their are much less and better ways that are not seen; gaskets that sandwich between components are more durable and unobtrusive to the eye. Air sealing has to occur during the framing stage, not after or you have this kinda ugly stuff going on.
I wonder if something like the Dow Froth-Pak would be ideal here. It would expand to fill any variance or gap and ensure a 100% air seal. The only negative would be if misapplied it might expand too much and be unsightly. In that case one of the tapes shown would be the cleaner solution.
Why not on the sill plate, put down 2 beads of silicone, 1 near the inside, 1 near the outside, then the foam, then repeat ? No unsightly tape and it's sealed between the concrete and first board very well ?
Would a double layer of sill sealer be an option? I would imagine that is the cheapest/most convenient option. Sounds good in theory, what do you think? Caulking is great in theory as well, but it needs to be a good brand/mix, otherwise it usually breaks overtime.
Thank you for video. I know you're a believer in fluid-applied (liquid-applied) water-resistant barriers, is there any product you would feel safe using instead of caulk/tape? Just to be clear, I have faith in the quality of the tape, just not the person properly installing it.
We have an old house and our contractor used the yellow “great stuff” in a can to fill in the gaps between our wood framing and concrete block. Is that effective for sealing?
Maybe for air, probably doesn’t help much for bugs. I have a older house I’m about to reside, thinking pulling the bottom rows of siding off before the siders come and using liquid flashing.
I am getting a metal garage installed on my concrete slab and was needing to know would this work from a metal sill as well? What is also good for the out side part to put in place to keep water from getting in the bottom part of the sills? Metal and some kind of good tape or special caulking? Thanks in advance.
We have a very forgiving climate in most parts of Australia, and we don't tend to use HVAC systems 24/7, so condensation, snow, and ice aren't really issues of concern for most Aussie homes.
How do either of those exterior tape products seem to hold up in the long(er) run? Seems like anything that's in that part of the house is going to have a tough life.
Does anyone know if I could use Protecto wrap instead? It's window seal. Within a week or two I'm doing work around my seal plate. I already had the crawl space incapsulated.
we used 8067 a couple of years ago in our home and contacted 3m first. they recommended using their Super 77 spray adhesive as a sort of primer. this worked well and was very quick and easy apply. the tape seems to have held up well so far. we're in climate zone 6, so quite a temperature range.
How do u seal if home is already built. I've been in my home less then a year I went into my crawlspace and in some places I can see outside of home n have alot of dampness n moisture
Nice video. Always something to learn. Thank you. Just subscribed
Helpful information. It's nice having an airtight home. On the flip side if moisture ever gets in your walls you've effectively sealed off one of its primary exits. I guess if you're going for airtight, you should also go the extra mile to make sure that moisture never gets in, if it does, it's going to do more damage and the repairs will be costlier.
SIGA Tapes are vapor permeable, allowing moisture to exit the cavity (without allowing any in), preventing mold and rot!
That's why you need to consider HRV/ERV systems when tightening a building. Seal it tight, ventilate right.
Yes because old houses never have rot or mold problems. Their ability to "breathe" with massive air leaks always comes to the rescue without any downsides whatsoever.
Matt's videos have been very helpful as I bridge the gap between commercial and residential construction. Using the primed tapes to seal from the sheathing to the foundation is essentially a lighter version of what we recommend in the commercial world. As long as there are no large gaps between the two substrates and as long as the surfaces of the foundation aren't soiled, I'm in complete agreement with this approach. But, sealing from the inside - whether with caulk or tape - isn't air sealing at all. Because of the seam between the sheathing and the bottom plate, air barrier continuity is broken where the sheathing meets the foundation wall. If you're not sealing the sheathing-to-foundation interface from the outside, in my opinion you're not air sealing. You're probably not bug sealing very well either.
Sealing the framing/concrete joint also has the benefit keeping the bugs out. It sounds like the tape, properly applied, would work great but I'd also caulk the joint as a backup. It's cheap and doesn't take long to lay a bead around the building perimeter.
How do you conceal the tape on the concrete? Does the siding hang down a few inches???
Yes siding hangs down over it...1” minimum
Hi Matt! Thanks so much for sharing your expertise with such clarity and great presentation! I have a huge problem. My brick ledge is only three inches. No room for exterior insulation 😢I need to extend my brick ledge. Any suggestions? Please! It’s getting cold here in Michigan. Thanks again
Matt, the building trade needs to 'take in' and accept your views. What you are preaching is very important, it needs more publicity, the law behind it, and promoting. Thank you. A Limey from you can guess where?
I've watched several videos that Matt has made concerning sill plate sealing. He has promoted several different products, from a foam strip, to a neoprene strip, to an accoustic caulk. Which is best???
Very good info.
Matt, when sheathing - is it best to flush the outside of the slab with the outside of the sheathing? And install bottom plate 1/2" inside of the slab? For ease of air seal taping... Or, install sheathing so it overlaps the slab? Ansd then dealing with the 'step' under the sheathing edge? ..In each case, raise the sheathing up by 1/8 up 'n off the slab? What's optimal?
@Sailing Chloe, I have the same questions....did you ever get more information?
I personally think both would work fine so long as you fluid apply when you in set it 1/2 inch. I would give it more like 1/4 gap. Concrere can release moisture I wouldn't want to trap it in there only using a tape. Personally I don't see any benefits from in setting it 1/2 anyway though. It might make it easier to straiten the mudsill I suppose.
Great tips!
What do you use as far as a siding or trim product to cover up the exposed tape on the concrete?
As shown, it’s for siding. Siding typically covers about 1” minimum of the slab. You can also use a fatter tape for brick ledge.
The answer is to use more Polyester Breathable Fabrics everywhere, 100% airtight homes are not possible, but breathable and increased airtightness are, I have argued for years the top plate must be sealed, in fact all homes must be made weatheright and air tight, and this is where Dupont USA should lead and educate us all. One day all good homes will be TYVEK WRAPPED homes, not just a few, but 100% of all new builds.
its not code to use tyvek across the US?
When sealing the outside, how does one handle lapping of the tape? Best practices for window detailing might lap housewrap (or similar) over the top of sealing tape. (I've repeatedly heard "Think like a raindrop, act like a leaf" at green building seminars.) However, as shown in the video, any failure of the adhesive might route moisture onto the sill plate. Also, there are regions of the US that must deal with termites. It seems like the sealing tape might have a secondary benefit there, but it would be illuminating to hear how detailing might change to accommodate this application. Thanks!
I’m not a builder so don’t take my opinion too seriously. He tends to use the zip system so there is no house wrap. It’s built into the sheathing. I imagine if you have a very low window close to the foundation, you would use the siga tape first. Then use the zip stretch flashing at the bottom of the window so it overlaps the siga tape. I guess if you are really concerned about the siga tape peeling at the top and becoming a water trap, i guess you could go over the edges with something like the zip system liquid flash. It’s the same stuff that’s used to seal all the other openings for pipes and stuff.
We use Tamlyn products with Hardie panel and lap siding; how would those products be installed to hide the tape at the foundation wall. Tamlyn sections show the product flush with bottom plate and sheathing, not overhanging it.
Do your siding projects ever encounter this detail?
Appreciate your content, as always.
Matt, great topic to tackle. This detail is very commonly missed and also education is limited.
As a carpenter for forty years if I saw this type of air sealing done to my framing job I'd be sick my job had this mess all over it...same with walls! Their are much less and better ways that are not seen; gaskets that sandwich between components are more durable and unobtrusive to the eye. Air sealing has to occur during the framing stage, not after or you have this kinda ugly stuff going on.
So, where do you buy these products? Delta HF Primer, specifically?
I wonder if something like the Dow Froth-Pak would be ideal here. It would expand to fill any variance or gap and ensure a 100% air seal. The only negative would be if misapplied it might expand too much and be unsightly. In that case one of the tapes shown would be the cleaner solution.
Why not on the sill plate, put down 2 beads of silicone, 1 near the inside, 1 near the outside, then the foam, then repeat ? No unsightly tape and it's sealed between the concrete and first board very well ?
This is exactly the process he started recommending a few years later… you were ahead of him… :)
Would a double layer of sill sealer be an option? I would imagine that is the cheapest/most convenient option. Sounds good in theory, what do you think? Caulking is great in theory as well, but it needs to be a good brand/mix, otherwise it usually breaks overtime.
What about metal framing? My framing is the galvanized metal. What is my BEST option for 100% sealing my bottom plate to the Concrete?
Thank you for video.
I know you're a believer in fluid-applied (liquid-applied) water-resistant barriers, is there any product you would feel safe using instead of caulk/tape? Just to be clear, I have faith in the quality of the tape, just not the person properly installing it.
We have an old house and our contractor used the yellow “great stuff” in a can to fill in the gaps between our wood framing and concrete block. Is that effective for sealing?
Maybe for air, probably doesn’t help much for bugs. I have a older house I’m about to reside, thinking pulling the bottom
rows of siding off before the siders come and using liquid flashing.
if I plan to seal inside with spray foam at the rim joists, should I also seal on the outside? shouldnt one side be left open for water to escape?
I am getting a metal garage installed on my concrete slab and was needing to know would this work from a metal sill as well? What is also good for the out side part to put in place to keep water from getting in the bottom part of the sills? Metal and some kind of good tape or special caulking? Thanks in advance.
Hi Matt, love the advice. Question...how effective is an expanding spray foam insulation or a flex seal rubber spray type? Inside and outside.
He doesn’t care
Matt, what about air sealing the outside with these tapes underneath siding where the sheathing meets exterior wall (crawlspace in my case).?
USA is so far more advanced than Australia in sealing homes - our average builder is really not concerned at all. huge gaps everywhere.
We have a very forgiving climate in most parts of Australia, and we don't tend to use HVAC systems 24/7, so condensation, snow, and ice aren't really issues of concern for most Aussie homes.
How do either of those exterior tape products seem to hold up in the long(er) run? Seems like anything that's in that part of the house is going to have a tough life.
why not use zip liquid flashing?
Where can you purchase Delta HF primer?
Does anyone know if I could use Protecto wrap instead? It's window seal. Within a week or two I'm doing work around my seal plate. I already had the crawl space incapsulated.
I know this is an old video but why does that bottom plate look to NOT be pressure treated?
I have water coming in at the wood-concrete joint. Help please.
Great, thank you.
+Matt Risinger Have you used 3M 8067? I've had good experiences with it. It's super sticky, even below freezing, and easy to find.
I've heard good things about that 3M tape but haven't had the chance to use it yet.
we used 8067 a couple of years ago in our home and contacted 3m first. they recommended using their Super 77 spray adhesive as a sort of primer. this worked well and was very quick and easy apply. the tape seems to have held up well so far. we're in climate zone 6, so quite a temperature range.
WHAT ABOUT SEALING WHERE THE WALL STUDS MEET THE INSIDE WALL
Where can the primer be ordered from?
How do u seal if home is already built. I've been in my home less then a year I went into my crawlspace and in some places I can see outside of home n have alot of dampness n moisture
Do you have a moisture barrier between the ground and your house in your crawlspace? If not that'd be a good start
you need to solve the moisture issue
Why not use a 2" roller and waste 1/2 the primer?
That DAP is garbage (no wonder its your sponsor) , spend the extra dollar and use 100% silicone.