SUB SLAB INSULATION - THERMAL INSULATION

[@todd5963]

You're a great educator, u made this easy to understand! Thx

[@stevenbaczekarchitect9431]

Thank you

[@11202]

Your wealth of knowledge is insurmountable and your educational value is insane. Thank you for all your content and you'll forever be present all throughout the multiple grandfathered buildings on my property throughout all the "renovations" I've done and will do. If you're ever up in Montreal/Quebec for a vacation I've got a barbeque dinner for you on the farm. And a place to stay, anytime.

[@MrCannonls]

We recently poured our slab in the basement. Held the gravel down 2” below the footing and then used medium density spray foam and ran it 12” up the foundation. Works very well and was much easier to manage during the pour.

[@jacktoy3032]

Nice video. It would have been nice to have still pictures or time-lapse videos of the installation that you described in the mockup portion at the start of your video.

[@wesrobinson7366]

This is such great detail on how to build with insulation in the basement. One thing I have also seen is using Rockwool on the outside of the wall slab. Since it can be in ground contact I was thinking of using that on my next build then using the same insulation here on the inside.

[@Austin-fc5gs]

I was just looking in to this detail. Please stop reading my search history 😮

[@stevenbaczekarchitect9431]

I will try but my ESP is full throttle all the time......

[@samuelfeguer]

Living in a home built in the late 90s I wish I had insulation underneath my slab foundation. The floor is incredibly cold.

[@stevenbaczekarchitect9431]

It is a difference maker, and certainly noticed in its absence

[@zipperpillow]

Move. Problem solved.

[@toddyuill3924]

You can ad it on top with plywood on top of that works great I had to do it in one of my basement apartments

[@lindacgrace2973]

OK, the votes are in: the Vibe board is MUCH better! As soon as you figure out how to lock the screen image (if that's not a feature - talk to the Vibe techs and insist that be included as a feature!) you'll be good to go. The seamless ability to zoom in and out, include or erase layers for clarity is wonderful aid to understanding. Great job, Steve - keep up the good work.

[@stevenbaczekarchitect9431]

I am learning still, but thank you for the positive comments!!

[@TexasBestBarndominium]

❤

[@DaveIngle1]

Hello Steven, I've been watching you and Matt for years. I didn't see any discussion of Radon mitigation with in this video. Is that because where you are Radon isn't an issue? When I did a cabin project 5+ years ago in Northern Wisconsin, they required a continuous plastic layer over my ridged foam. FYI, the insulation is definitely nice but, I also added radiant heat throughout the slab... in the winter months... Very Nice!

[@POLOLOUS3]

Another great vid Steve. Do you have any previous videos or an article I can reference on continuous insulation/thermal break vs thicker/higher r value between studs?

[@stevenbaczekarchitect9431]

Check out my catalogue of videos on the Buildshow Network buildshownetwork.com/go/stevebaczek

[@morganoverstreet6824]

Something we did a bit different that I havent seen anyone mention- I used "ideal walls" (former superior wall employees started a new company) Since I am using radiant floor- we did R10 foam underneath the slab as usual- but since the bottom 4" "beam" that goes around the perimeter of the walls is not insulated- we cut a 10" piece of 2" XPS and glued it to the exterior of the foundation all the way around the bottom in an attempt to mitigate heat loss from the heated slap at the edge and also provide a thermal break. basically we did the same detail you mention in this video but on the exterior so that the concrete itself was pushing against the foundation

[@toddyuill3924]

I noticed the plumbing is too close to the wall to insulate proporly and was wondering if you have a sprayfoam guy coming why not do the whole wall so its water and air tight im just wondering if im missing something or if im doing it wrong love your vidios thank you for making them

[@AGClaymore]

Steve, is there a reason for not taking that lower layer past the edge of the footing? It would cost more in gravel, I suppose, to lift the whole thing and you'd need to pour a higher wall to keep the headroom but wouldn't it be better thermal performance? Love your channel!

[@CarolinaDruid]

Great video, as always! I remember seeing one video you did, where the project used glavel for subslab water management and insulation. Would you recommend still using a layer of rigid foam between that and the slab?

[@stevenbaczekarchitect9431]

No, "Glavel" has a R-value of R-1.7/inch so a 10" footing gets you R-17.

[@gulfwalrus]

Steve, Great videos and information! I am designing and building a home and had a question that I've gotten 2 contrary answers. I'd love to tap into your knowledge and get your take. You said holes up on the permiter drain which makes sense but what about grade on the pipe? I'm planning on using perfed pvc and I've heard anywhere from "no grade" all the way up to "1/4" per ft". My thinking is a slight grade but curious what you'd recommend?

[@perrymallas227]

Can you do a vedio showing how you would finish the basement wall?

[@stevenbaczekarchitect9431]

I did, here you go..... buildshownetwork.com/contents/insulating-the-basement

[@VernBigDaddy]

Hey Steve. Im getting more and more plans to estimate for insulation where the plans look like cartoons and are printed to look hand drawn. I HATE THEM! Its harder to scale pages in my estimating software and the details tend to be muddy with color & scribble lines. I hat do you think of these type of plans. Im a believer that “if its not broke, don’t fix it!”

[@stevenbaczekarchitect9431]

All I can say is that I take pride in the work our office does, we don't do cartoons

[@ericmetz2286]

Thanks for the great video. What climate zone(s) would you recommend this for? I'm in Southern New Jersey (zone 4) and I'm continually getting told "that's not the way we do it here". I'm looking to use Superior Walls and I have not been able to find a source providing that detail. On a previous video of Steve's, he used a sheet of ??mil poly over the foam to keep the foam from "iceburging" when you pour the slab. When is/isn't the poly necessary? Thanks again.

[@keithpomeraning9784]

10 mil poly.

[@scottwolf8633]

Why not utilize the thermal mass of the foundation walls by insulating the outside of said walls?

[@stevenbaczekarchitect9431]

I favor insulating the wall from the inside. It's protected, easier to install, in many cases less expensive, and while there may be a very slight advantage to using the concrete wall, the complications of protecting the exterior insulation when it breaches grade is always a challenge

[@scottwolf8633]

@@stevenbaczekarchitect9431 Thanks.

[@liberaljoe]

Question. Why not insulate the outside of the wall? Then could make it continuous with the insulation on the wall of the house. Pros cons?

[@scottpaulson1714]

Could you also use closed cell spray foam as your insulation as well?

[@Scott-cu4ol]

If the ground doesn’t bleed air, how does radon get into the basement if you don’t use a good vapor area under the slab

[@stevenbaczekarchitect9431]

That is a good question, I am not a geologist, or soils engineer.......but I have done blower door tests before and after casting the slab with no change in Air Leakage. My best answer is the Radon is a very, very slow bleed...

[@Scott-cu4ol]

@@stevenbaczekarchitect9431 thank you. I think the process would be complete If you just added the yellow vapor barrier and taped all the seams before you poured the concrete. it would be one more step but I think it would then make it 100% radon proof. perhaps at that point, it would be more cost-effective to just use closed cell spray foam which would accomplish everything in one shot.

[@59seank]

Steven, have you ever made a house foundation out of treated lumber and plywood?

[@stevenbaczekarchitect9431]

Not yet (hint hint).......standby, something might be coming out this spring to discuss??

[@59seank]

@@stevenbaczekarchitect9431 I hope you get to try one! It seems to me that wood foundations for small houses would be a great cost savings. We also have amazing new products to shield treated wood from moisture.

[@DeuceDeuceBravo]

Love the early morning videos. 👍 In this scenario does the polyethylene layer still run under both layers of insulation?

[@stevenbaczekarchitect9431]

It could run over the top, or under, the result would be pretty much the same. Contractors like it on top because when it is placed under the rigid insulation slides all over the place

[@GallatinMan]

Any issue with adding in a poly vapor barrier both under the 2 foot footer & under the slab?

[@rjygrahamt6c]

Was cost a factor in choosing to do concrete pour + EPS on the walls vs an ICF block?

[@stevenbaczekarchitect9431]

ICF in our region isn't even a close trade off. I get asked ALL the time why we don't do ICF.......when we price it, it is clearly dropped from the discussion

[@speedbird300]

Is no vapour barrier required?

[@stevenbaczekarchitect9431]

You can put one in, it won't hurt anything. The rigid insulation is semi-permeable so it will drastically slow any moisture migration into the basement

[@michaelhand9769]

is there any reason to not have the top of slab to be flush with the top of the footing to gain the extra 4", to have a minimum 8' of height (not including the sill plate(s))?

[@solomon8702]

Why not both layers over the footing? Its large mass can use more r value, especially being at the perimeter

[@Susan508.1]

How is the slab attached so it doesn’t move. I guess it’s Just gravity? Is that right?

[@stevenbaczekarchitect9431]

It is pinned between the walls laterally, and the ground below it holds it up....

[@jwristen24]

Closed cell foam is the way to go there.

[@DitDitDitDahDahDahDitDitDit]

Steve, Have you ever asked an engineer who does radiative and thermal heat transfer calculations for some simple estimates on how much heat flows into a building from, say, the roof deck and the walls. Put another way, radiant energy absorbed into a typical roof deck during the worst few hours of the day, as compared to the mostly convection transfer of heat across walls, as I’m trying to conceptualize things. A simple - model - back of the envelope day and night comparison could point out basic principles. I ask because, from a practical point of view, model comparisons like this could help builders and clients know where they can get the most bang for their buck. And guide better renovations. Building new houses that do everything at once to the nth degree, and to the nth cost too, is a ball to watch, and we learn lots from it, but not practical for most construction nor most wallets. I hope someone is writing this kind of textbook for the next generation.

[@jdaz5462]

That foam has gone crazy in price. It's almost 60 bucks with tax for a 4x8 sheet 2" thick. This ads almost $6000 to the typical 1500sq foot slab.

[@Notch8]

If you have Menards near you they carry the Type IX. Look for the Insulfoam. 2" is about $1 sq/ft.

[@daviddbl.d2278]

Steve can I ask you a question. The drainage pipe you drew in you have the holes in the up or top position. I thought that if the holes were on the bottom when the water coming up finds the holes and runs to the sump pump or going to the outside. Thank you David

[@stevenbaczekarchitect9431]

This pipe drains to the outside via gravity, holes up/ holes down is always a question.