5-Layer Slab System for High Performance Home Build

Home Diagnosis TV series co-host Corbett Lunsford shows the installation of the 5 layers of performance control under his family's new house. Thanks to Royal Building Products, Rockwool Insulation, Stego Industries, and the subcontractors who worked so hard to get this right!
More at: HomeDiagnosis.tv/atlanta-home...

[@marcustait79]

Loving your philosophy on how you value skilled labour!!!!👏👏👏

[@HomePerformance]

✊

[@jorgeantelohollweg5273]

I am enjoying this so much!!!! Keep going Corbett!!

[@javierluna56]

Great video and great advice. As a residential and industrial contractor, I never deal with customers who haggle. Quality work cost money and I wont hire crappy subcontractors. Many customers who didnt hire me because they hired the cheaper guy, have called me back to fix sub standard work. It costs more to tear down shotty work and redo a project. Customers always get what they pay for.

[@HomePerformance]

Amen

[@StephenRardon]

Awesome to see more progress!

[@HomePerformance]

Thx brother

[@danthesupercontractorhvac9690]

I appreciate the last comment, I tip my hat to you good sir.

[@Johnintoit]

Nice to see high performance builds popping up more often, I'm a contractor in Ohio and I am building a Passive house this summer for myself. My only real concern is the Rockwool under slab, I am huge Rockwool fan and will be using it on my build (exterior insulation) but the concern is that while it cannot to be harmed by water it sill has the ability to absorb water given enough contact time and no real way to dry out so it may just be a like a damp sponge, hope for the best there. Only other thing i would suggest because your in a high Radon area is to use a primer then tape approach when attaching your vapor barrier to the concrete, good luck on the build I look forward to the updates.

[@HomePerformance]

Thanks, John, and good luck to us both

[@SawHorseDesignBuild]

Water passes through ROCKWOOL and it does not wick up the moisture. That is why it is a good control layer below the slab, siding, and roof.

[@rollandelliott]

totally agree wet insulation is worthless hopefully they have good foundation drainage and it never gets wet?

[@melvin_0bviously]

Rockwool on top of 6” of gravel though. XPS also works here if you were looking for an alternative.

[@dh66]

​@@melvin_0bviouslyEPS>XPS. Degrades slower, is lighter and still has great pressure resistance for under slab.. More available AND CHEAPER as well

[@terrybrown5883]

MATT Reisinger and associates all are Great Help

[@elliotgold]

I’ll be incorporating some of this into my “budget” high performance cabin. I like 2” slab. I was worried about concrete costs for a 4” slab in the crawl space. You make a good point, it’s not structural.

[@HomePerformance]

Great! Good luck buddy!

[@majala23]

Looking forward to seeing the humidity/radon levels. Great job!

[@HomePerformance]

Thanks, us too

[@jorgemach___2162]

there will not be ANY that is also the point of all this extra good stuff

[@HomePerformance]

haha, yep, zero humidity, zero radon. it's dry, but it's honest.

[@shakejones]

Great video+explanation+presentation! Thank you SO MUCH for sharing your knowledge! Well done mate - NEW SUB 🙏🏻

[@HomePerformance]

Thank you brother, glad you found us!

[@premiercconstruction]

Challenging soul conditions, high radon area, termites... all tough challenges. Looks like you are doing amazing job. Lots of thought put into project. Probably best foundation in area hands down... Love rock wool insulation best stuff for sure. Careful that it does not get super wet. Why not put the liner under the rock wool? Also I hear it’s better in walls as well as compared to spray foam which has lots of off gassing and can hide termites and water damage issues.... I always go 4” min on something that big. Also I solute slab from footing wall. I have to say I’m liking your videos more and more. You are definitely a critical thinker and not out to simply reinvent the wheel. Thanks for sharing... and great treatment to those who are working for you....

[@HomePerformance]

Thanks a lot brother

[@abel5925]

Love your videos, If HGTV or someone had you they’d be making a real difference for our country

[@HomePerformance]

Guess what Abe! We’re on PBS: Home Diagnosis TV Show kzbin.info/aero/PLsc2-5fAgMq4KVStYsKKrAfTOI7s8JKUy

[@nicpedia2432]

I tried talking my concrete sub into doing XPS or EPS foam below slab. He told me I was crazy and that was never done here. Building design needs to improve like this. Great video, going to have to review the other ones of yours.

[@HomePerformance]

Thanks for the follow- yes, I'm hearing every time my inspector visits that no one has ever done any of this in my town before

[@HomePerformance]

It’s a system, remember- the 6” of gravel underneath breaks hydrostatic pressure, the drain tile drains, and the radon fan evaporates and exhausts what little water remains. Yes, this is a system that can work in other climates, but you should think through any design carefully.

[@MrGbSandwich]

American are funny in sweden its normal since 40years? to have insulation below the slab, (the edge and footer aswell) normal insulation thickness is 300mm eps s80 ,XPS . incase of high loads on slab. insulated concrete slab are fine up to 40-60 kN/m witch you can build up to 3 storeys with.

[@george.carlin]

@@MrGbSandwich They aren't funny, they just a couple of decades behind. That's normal to be behind in something, like building techno. States, on the other hand, came up with OS and iOS, with the internet, with many great software programs. You Swedes are great too, every time I use laminate flooring I enjoy how simple and yet smart it was designed and three-point seat belt saved my son's life. What is beyond my understanding is why you brought one million of 3rd world people into your beautiful country. It will not end well for you.

[@cwehbe]

You need to find a new concrete sub my friend. I have not built a house without sub-slab foam in over 10 years here in the midwest.

[@6stringsandapick]

Looking great! Remember, when you haggle on price, the contractor looses money which does not make them happy, which means sub par work. I typically include a box of doughnuts or a nice BBQ lunch for the crew for crews on occasion, helps break the ice and puts everyone in a god mood.

[@HomePerformance]

I brought beer to celebrate the pour. Whatever works.

[@8Hamo]

Nice Corbett..

[@rhd244]

Good video 👍

[@HomePerformance]

Thank you

[@J8n3eyr3]

You had me at "weird dirt."

[@HomePerformance]

The weird dirt had us on day 1

[@Sailor376also]

In northern climes you have an error. Possibly even for Atlanta. The slab you just poured is in contact with (the exception being a 15 mil sheet) with the rail footing and the concrete foundation wall. No. The slab temperature is governed by what it is in contact with. Concrete has an R-value of less than R-1 per FOOT,, maybe. So,,, why did you bother with R-10 under the slab? You will have about an R-2 average yield. Thermal conduction and thermal bridging. Don't pour a thin slab. Pour a thick slab, the slab can become not an enemy,, but a benefit,, a thermal flywheel for the house. (Cool or heat the slab,, and the house will be cool or warm. Cool with night air,, heat with sun,,both are free.) but, Isolate it from ALL contact with footings, soil, and outside air. If the slab is only in contact with the interior air , it will be the same temp as the interior air. Fiberglass speeds the set time. Pouring on insulated foam increases the set time. A 2" slab will not generate heat anything like a 4 or 5 inch slab. and a 2" slab on foam should not be walked upon for finishing. Bull float it well and leave it alone. 2" slabs work very well. I would use a higher bag count, which also increases the heat. In Atlanta,, only try that pour in the winter. At 80F and sun, your set time will be in minutes. In any other than winter, use retardants, or a 12 man crew. Isolate your slab. And,, the vapour/water barrier goes under the sheet insulation, not over it. The R-value of your insulation is based upon a dry insulation. A rockwool insulation can be wetted . A wet rockwool insulation has no R-value. Rockwool or foam insulation should be on the level above the rail footing, and perimeter isolation band can be accomplished with a burial grade pressure treated 2X4, or 2X6,, ,,or,, high density poly-isocyanurate (uncommon),, or high density urethane foam 3 to 5 pound density works well, or even pumice bricks. (used for cleaning ovens and grills) My first isolated slab was 1983. I've made lots of mistakes,, no reason you should not benefit from my misdeeds.

[@HomePerformance]

Thanks, Sailor, and just so it’s clear, we used energy modeling to specify the exact R-values. I’m familiar with thermal bridging, but what we’re demonstrating on this channel is how anyone can achieve a high performance home without driving their team crazy. Btw, our cooling load is already just 1.5 ton, the smallest split system you can buy, so further insulating anything would actually DEtune my enclosure and HVAC from each other.

[@Sailor376also]

1.5 for your locale is impressive. You are doing good things. Ours, north of Detroit, the last one I built quite a few years ago,, no central air, a water chilled A-coil,, about a 1/2 ton yield,,(de-humidifies) , heating, a detuned,, burners removed, 3,000cfm,, but just 100,000 BTU. 3200 net square feet + full walkout level. Gas bill on the order of 600-700 per year. (gas, heat, hot water, stove, dryer) Quad glazing, walls fiberglass12" over all. Zero pipes or ducts in outer walls. I'd like to suggest you think seriously about a thicker, completely isolated slab. Thickest I ever poured was 10" with 500 linear feet of ribbed 4 inch tubing cast in,,,,, Winter sun warmed air collected from the top of the house by some slow shaded pole motor fans. Ductwork from top of house to basement floor,, and into the floor slab. 81F sun warmed at the top was 79F as it entered the basement floor, and exited perimeter floor registers (16) at 73F. In January, a sunny 20F day,,furnace almost would not kick in until Colbert monologue.

[@Sailor376also]

You have raised some excellent points. I have normally used sheets of foam. But in Georgia, and many areas, termites and some ant species are a problem. And different foams are assaulted by insects differently. White bead board, Styrofoam, is an excellent foam to bury, except where ants or termites may relish it. The benefits of white beadboard are A. cheap,, B. available, C, it is moisture permeable (If it gets wet, it will drain out.) It should never be used near the surface,, there are too many ants that love it. Quasi enclosed under a basement slab,, works well. Closed cell styrene,, blue, green, pink,, closed cell,, much less susceptible to ants, water proof cheap, available. Many areas, northern tier, this is the preferred foam for burial. Not termite proof. Urethane and polyisocyanurate, expensive (by comparison) Insects,, I don't know. Barrier. My preferred plastiuc sheeting over the years has bee a 6 mil designed for crawl spaces. Broken concrete and rerod will not poke holes in it,,, very stretchy and tough,, a polyethylene cross-linked? Just straight 3 mil poly works well buried,,, sun will never get to it and it is most UV sensitive. Most stone bases will not puncture it,,, however,, in my area,, I am normally using pea stone or sewer stone,,, both are riverine rounded. If I were using larger crushed stone, sharp edges,, I would first reach for the cross linked 6 mil crawl space poly. But,,, I could use sharp stuff and then top with pea stone or even sand. You would only need to dress the top,, no discernable layer. I have never done it, but foam cost is primarily per cubic foot. Two 1.5 inch thicknesses will cost the same as one 3". Place the poly layer between. The major point I have learned is what I call detailing. The new concrete will be poured into an isolated 'swimming pool'. The concrete shall at zero points be in contact with soil, footings, poured or block basement walls, or outside air. Zero. The layout is ultra efficient,,, run your sheets tightly butted down your first straight wall,,, the custom cut at the end,, the waste piece becomes your new beginning piece. If your seams are not far enough apart,, first row begin with a full,, second row begin with a half or one third sheet,,, waste pieces are brought back to begin the next row. The smallest pieces,, save until done,,, and with beadboard or the pink or green or blue stuff,, you break off pieces with your hands and fingers and hard pack them around pipe, duct, or electrical intrusions,, until,, zero concrete can fall through to the soils or fill. It goes fast. I have insulkated a 1500 square foot basement slab in one hour by myself. Perimeter. so your slab does not contact the basement poured walls. My most normal material to reach for is burial grade pressure treated wood. Note !!! Burial grade is NOT normally stocked by anyone. It must be ordered by a knowledgeable person well in advance of need. the usual lumber yard guy will ALMOST without exception,, sell or order in ground contact grade. Ground contact grade,, IS NOT burial grade. Only use burial grade. Another excellent option for perimeters,, again special order,, knowledgeable person,, high density urethane foam. Urethane foam can be ordered in pounds per cubic foot, ppcf from one pound per cubic foot,, up to ten pounds per cubic foot. What does the supplier have? a 3 to 5 pound foam works well. Last option,, and I have used it once. Pumice bricks,, commercial kitchen supply house. Pumice bricks will never be eaten by any critter, and they have an R-value of about 2. I never have,, but you could use a cheap foam, just to preserve the space,, asphalt impregnated expansion strips,,,, one or two thicknesses,, and then cap with, infill after with a conventional self leveling parking lot expansion joint urethane filler/caulk. Throw your roll screen or road screen on top or shovel a few spoons of pea stone on top to keep the wind from blowing your foam around. Concrete generates heat when it cures,,, atop foam insulation,, when it begins to get hot,, it cures faster,, and gets hotter,, and faster,,,, you get the idea. When it fires off,, it happens fast. I use retardant in my mixes so that total times and times to finish trowel feel normal. Adding chopped fiberglass to the mix can greatly accelerate the cure too,,, I don't know why. But I had one really warm day 20 years ago,, I was walking on the concrete while it was still coming off the truck. Yep,, that fast. I isolate nearly every slab in my constructions now. My unheated workshop,, the latex paints never froze. Garage floors,, the cars are always above freezing. We think of concrete being damp and cold,,,, but it is not. The ground underneath the concrete is damp and cold,,, not the concrete. If you want a warm dry slab,, one that helps keep the house warm or cool,,, it is just a great flywheel,, that moderates the temperature. If you are going to pour concrete inside a house,,, make it work for a living,, helping to heat or cool the house,, instead of requiring heavy HVAC loads to heat and cool the concrete that is as cold as the soil below,, and just as wet as the soil below.

[@tg-bh2up]

@@Sailor376also Going to build north of Detroit how to contact you Sailor

[@Sailor376also]

Glad I could help. That is exactly why I took the time. I did, and did not use the 'pick two',, just a different way of looking at the same thing. Calculate the cost of the improvement, calculate the money saved,, by building better, stronger, more insulation,, whatever. Money has a cost and a value,, and money can earn interest and make money. So,, if you invest in a high yield investment,,, or you invest in more insulation,, which pays you back better or faster? Choose the better return, either stocks, or insulation.. There is no such thing as a 20 year payback,,,,, you should have invested in the stocks and bonds and paid the increased energy cost with the profits. I always calculated and watched for a maximum payback of 7 years. Most 'improvements I ever attempted were targeted of a payback in 5 years or less. Some few,, I would stretch to a payback of 8 or 9 years. You also must watch for over lapping 'improvements'. If you have already saved a 100 dollars,, will the next improvement try to save the same 100 dollars? Apply that thought to all aspects of the house you build for yourself. Cheap shingles may be the best, cheapest, economic choice,,, or a copper roof may be the cheapest roof,,, you run the numbers to decide. Rule of '72' . A seven year payback equals about a 10% per annum return on investment.

[@stevehvac1]

Very informative

[@HomePerformance]

Thx Lee

[@Forrest-Jackson]

You had me at "we should be paying people what they're worth."

[@HomePerformance]

✊

[@rockwashburn8895]

Absolutely, cheap labor isn’t skilled and skilled labor isn’t cheap.

[@kevinm5564]

Good video. Thanks for sharing. Just a note Its not fiberglass its polypropylene, and Im a big believer especially in thin applications.

[@HomePerformance]

Thx Kevin

[@chrisrhudy2000]

I have experience with a 3 inch slab with rebar and it performed fine. of course it was in a basement tho. I put several layres of 20 mill poly under it and i didnt get any water infiltration whatsoever. I did put a drain under the slab otherwise the water that came in under it would have lifted the slab. My conditions were far different as i live in a flood plain and water was a major issue. in fact it was the issue i was trying to solve. The slab worked great the sub pump did not grr had to buy a high performance pump and spend way more money on it as the water infiltration problem was idiotically bad but the slab never lifted and the walls leaked not the slab. i ended up spray foaming the walls then covering them with tar and poly film. what can i say i am cheap af. but point is it worked like a charm and i had 2 feet of water standing on the outside of the foundation at several points after the final install so yay me no construction experience at all and i fixed a thing that contractors told me was unfixable.

[@ek9772]

chrisrhudy2000 there is a drain under the slab. It was installed previously on the footings with Form-a-drain. The forms allow the connection of the side facing the slab to the outside of the house with a tube bridging the footing.

[@HomePerformance]

Hahahahahahahaha

[@ek9772]

Great slab IMHO.

[@HomePerformance]

Hey, thanks Eric

[@ek9772]

Home Performance thank you. I like the fact that you are making an effort to keep VOC to a minimum - too many builders use materials based on cost at the expense of health. This includes people like Matt R.

[@Harold_Flite]

With payment systems in place like that, as a contractor, you should have no problems in getting your build completed. Just be sure the beer is cold....👍

[@DougCube]

How does using Rockwool for the underslab insulation compare to using rigid foam? In my build, I was planning on using EPS for the slab insulation and Rockwool for exterior walls.

[@HomePerformance]

Well, they’re about the same R-value per inch, but I believe the foam can break apart in freeze/thaw cycles, if that matters to you. Also, when we built this all foam insulation was req to have flame retardants, which is dumb imho. Now the state of CA has allowed for below grade foam to not have FR, so you can buy clean foam in the states for the first time.

[@jakefarron1780]

Thank you for the information - separate from the technical aspects, what song/artist comes up at 6:22? Lyrics seemingly unsearchable on Google

[@HomePerformance]

That’s our band Mysteriam, Jake! Here, you might love how weird the music video is: kzbin.info/www/bejne/Z2iXfamMlNaCm6c

[@ABZD019]

I was just on the Rockwool site looking at the Comfortboard 110, wondering if it had high enough compressive strength to sit under a foundation footing. The IRC prescriptive code allows foundation design for soils as low as 1500 PSF compressive strength, and at 25% compression Comfortboard 110 is 1566. I know EPS gets used under footings, but it might even be possible for Rockwool too. It seems like as much insulation is used under a slab or even the foundation wall, the footing becomes the largest thermal bridge. Why not eliminate that bridge entirely if you can?

[@HomePerformance]

Exactly

[@sketchapp3783]

Can you show how you're dealing with the wastewater and plumbing coming out of the crawl space. I'm always at a loss of how to plan for this when I'm thinking about a building. I want to be able to put down a crawlspace first then deal with the plumbing.

[@HomePerformance]

Stay tuned for the visual, but simply put, we left a 6” pvc pipe in the bottom of the wall form to run our 4” drain line out, and a 1” for the 3/4” water supply. Had to know where the sewer is, which in our case was weird.

[@Homeairquality]

Rockwool (aka. Was roxul) started hitting the AIA circuit hard a few years ago. Fast forward a few years and roxul is literally being used everywhere and for anything, with little data or history to substantiate its use for these exotic applications. #rockwoolpayingeveryonetopromoteitsuse

[@HomePerformance]

Hey Team- i first tried Roxul back in 2016 without being compensated at all, and continued to choose it over other materials because of its ease and effectiveness. I have since convinced them to become a product partner of mine, but anyone on that short list is there because I believe they make superior products. Just to add my two cents.

[@Homeairquality]

Don’t get me wrong, I love rock wool. But only for cavity fill applications. Kudos to roxul for pushing the heck out of this stuff. Good lord it’s every where!!

[@charliexu1099]

I wish I can see how the radon system & drainage system besides the Form A Drain Part get buried inside the slab. I see a white PVC pipe running horizontally in the middle of the floor area. Is that for radon ?

[@jimmiedow]

You mentioned in your Manual J video that sub slab insulation is "the last thing you do" because the thermal connection with the ground actually helps cool your house in the summer. Did you end up calculating that the heat saved in the winter is worth more than the free cooling in the summer? Is there a situation where you are actually better off by omitting the insulation?

[@HomePerformance]

It is helpful in our case because we got the roof, walls, windows, doors, and airtightness planned to be very good. That’s when it works- as a system with everything else.

[@hotrodhog2170]

Just found your channel. I assuming this is going to be a conditioned crawlspace. I didn't notice any vents. Is this going to be used as a cold air return for your HVAC system? I am an insulation contractor and helped a few folks with insulated crawl spaces. We are about 4-5 hours north of you and we insulate about 2/3rds of the slab and leave 1/3rd with no insulation and that acts as a heat sink where in the evening it releases the heat from the Earth back into the slab and that saves on heating costs in the winters. Any thoughts on that for you?

[@HomePerformance]

Hm, interesting idea, but an energy model would show that an uninsulated slab (or any portion of one) is a liability in cold months- it does a beneficial heat sink thing in hot weather. The two basically are a wash for normal homes, and only in higher performing homes does it become a good investment to decouple from the 55 degree ground beneath.

[@timm439]

The heat sink concept is used with hydronic radiant heat in the slab where you actively warm the ground.

[@garywilliams4070]

Corbett, do you know of a cross section detail diagram out there on the net of this five layer system for a slab on grade foundation ? I plan to use all five steps of your system, however I am building on a slab. It would really be helpful to show my foundation contractor.

[@HomePerformance]

Hi Gary- sorry, no, but you could easily create one using the details in this vid. Good luck with your build!

[@nc3826]

Slump test is a way of verify you get what is on the invoice... And since I did slump tests I know thats not always the case... no matter how much self confidences you have in urself and with your supplier...

[@tomroehl5126]

I'm curious about the way that the plastic comes up the side of the foundation... isn't there a risk of gaps in the adhesive if you are not super careful during installation that could allow water vapors to make their way into the basement?

[@HomePerformance]

Tom, there’s a two-inch adhesive out of sight, between the wall and the Pango, which is the main seal. I just wanted the option to double seal later and cut it nice and pretty once the slab is cured.

[@tcranston]

The compression loads are in PSI, not in "pounds per sq foot." You need a min of 25 PSI under the slab to prevent insulation collapse. Roxul will give up to 80 PSI, and most rigid 2" board is above 25 PSI, too.

[@HomePerformance]

That’s great, but they label the bags with psf- 400 and 1100, respectively

[@rollandelliott]

there is no thermal break inbetween the slab and the walls of the building? and if the house is buildt on piers I assume this will be an unvented crawl space?

[@HomePerformance]

Hey man, you’re making a lot of wrong assumptions on this one video. You should explore some of the other 100+ videos on our build if you really want to know this stuff- also, your profile pic gives every comment you make seem like trolling, fyi.

[@squeekhobby4571]

Great job! What is the cost difference if we use polyiso foam below the concrete

[@HomePerformance]

None, but you introduce toxic flame retardants

[@timm439]

Not sure what you mean, Corbett... Polyiso is a lot cheaper than rockwool.

[@polarunion]

What’s the radon metric you guys are using in your area? becquerel (bq/ft3) 19 bq/m3 would be considered acceptable.

[@HomePerformance]

I have kids and we want to spend tons of time here. I’m shooting for zero on every scale. But picoCuries per Liter is the unit of choice here.

[@polarunion]

Home Performance Absolutely. Not sure if you’ve taken any footage of your radon system. I’d love to see it. It’s something that does not get nearly enough attention. Great sub grade details. Looking forward to seeing more.

[@HomePerformance]

Stay tuned my man

[@Homeinspectorsny]

I agree I don't haggle on price but I make it clear on my expectations up front.I tell everyone there is no free lunch in this business.

[@rollandelliott]

wouldn't it be better to put vapor barrier under the rockwool insulation? after all that insulation is water vapor permeable. so if it gets wet the water will act as a thermal conductor and take the R value down to almost zero? one could put sand on top of the 57 gravel so the plastic would not get ripped.

[@lee-johnson]

I'm interested in a vid on the hvac load cal, duct design, equipment selection etc... As you can tell I'm a hvac contractor.

[@HomePerformance]

Already published. kzbin.info/www/bejne/jZXGp6xnbdF6naM

[@cynthiaarmstrong7972]

If you use rockwool under a concrete slab, you’ll inevitably get water under there, even with a barrier. Isn’t that going to fill the air interstices with water and destroy the insulating ability?

[@HomePerformance]

Our footings are drained, actually, so there’s probably no water at all in the Rockwool

[@CommentsAllowed]

7:40 Have you ever been like "whoa... that's double what it should be"? I found with contractors, if they don't want the job, they will give a 2x or 3x estimate.

[@dh66]

I'm doing a 5 layer slab as a rank amateur... Does that make ME high performance too? 😂 (Compacted dirt, clean 3/4- fill, 3" lapped EPS, 10 mil poly, 4" concrete with fiber and retarder)... Same insulation value as this, no worry about termites here and I can drive up to 3 ton trucks on it

[@2brazy4ubitch]

Hey all, how is the 2” slab performing? Any cracking, lessons, regrets, etc. or all good?

[@HomePerformance]

Perfect. No regrets about the slab, yes it cracked some but as expected. Nothing that prevents rolling around on a mechanics sled. FYI, perfectly installed 15 mil subslab vqpor barrier does not ensure low radon.

[@2brazy4ubitch]

@@HomePerformance So this is a “rat slab” under a wood frame floor bearing on the top of the foundation walls? Any provision for airtightness between living space and this crawlspace area? Assuming you put an exhaust fan in there to deal with the radon and would have been concerned about losing some conditioned air from living space above?

[@HomePerformance]

No, I would search all our crawlspace vids on this channel. It’s fully conditioned.

[@2brazy4ubitch]

Thanks, appreciate the response.

[@jonathanmilton9753]

Do you need to insulate the footers to meet net zero?

[@HomePerformance]

Well, we’re not aiming for net zero, but the energy model would tell you whether or not to, and by how much.

[@thefix2573]

Skilled Labor Isn't Cheap;Cheap Labor Isn't Skilled

[@HomePerformance]

Amen

[@MarkBates566]

no steel in the concrete?

[@HomePerformance]

No, too thin. Hence the fiberglass admixture.

[@rizonsolar7515]

Great Video, I'm trying to catch up on them. I also want to make an insulated slab lasagna for my high performance home. What are you thoughts on 4.5 inches of insulation under the slab and 1.5 inches of insulation on top of the slab? I'm thinking for cushion comfort on the subfloor it would be nice to have. I can't find any information on other people doing both, its either one or the other. Thoughts?

[@joulian0720]

I like ppl like this guy we make a lot of most off these folks lol. Millions and millions humans have been living in caves. It’s all just a game

[@HomePerformance]

My family lives in 200 sq ft for the past 3 years, I know of what you speak

[@brucea3103]

What is the cost per layer? I'm really interested in the Pango wrap, but it's hard to find a cost per sq foot on it. Also, do you blindly throw your wallet at your subs every time they quote you a price or do you have a rough idea as to how much each product costs and installation? You are doing the over-engineering that I want to do with my house, but I would like to think I will have an idea as to how much more it will cost vs. code. For instance, Florida requires roofing straps to hold it to the walls every so feet, but I want a strap on every joist. I will know the cost per strap times the number of joists, factor in the extra labor and can come up with a rough number. If the framer gets it in the ballpark, OK, but if it seems greatly inflated, I would question it and ask how they came up with the number.

[@HomePerformance]

Of course, always know what you expect to see, whether asking for bids or performing a diagnostic. Can’t break out cost per layer at the moment, Grace is the budget expert, but it’s worth it to do this for us, just as it’s worth it to tie every piece of wood together in FL.

[@brucea3103]

@@HomePerformance i wasn't trying to lump you in with the 'more money than brains' crowd, but I was thinking of the people that were new to your channel. Just accepting an invoice from your sub requires a fair amount of trust. That trust was negotiated at the beginning of the project by you evaluating and choosing your subs. I guess what I am trying to say is that a self-builder needs to know material cost, cost of labor and time needed to complete a task. Jen-Weld and Anderson windows install the same way. The only difference is material cost. However, if you want to go all Risinger on it and use a fluid membrane with a flash pan, you should expect to pay more in materials as well as time if the installer has to learn a new technique as well as follow-ups to insure it was done correctly. Knowing the base cost of an installation helps with understanding if an estimate is correct.

[@HomePerformance]

Right on, Bruce- I’d say there are a bunch of pre-requisite understandings AND common sense necessary for getting the most out of this channel, which would be distracting and probably tedious to dive into in this type of vid. Also, I’m NOT necessarily advocating for homeowners to GC their own project.

[@T.E.P.]

any after pictures of this 2 years later?

[@HomePerformance]

Yes, we’ve shot over 100 vids of this build and are now living in it. Subscribe if you’re curious.

[@andreasthomsen2669]

In which way is this high performance? In Denmark we use at least 300 mm eps, two inch is nothing? Form the looks of your coat its cold there.

[@HomePerformance]

Haha, definitely a different climate Andreas, and when I say 'high performance' on this channel, I mean 'achieving the specific goals of the occupant'. One of our goals is to avoid foam, because in the states all foam has flame retardants in it. Another is to tune the home's systems to be both cost effective and easy to live in and maintain, and 2" showed in the energy modeling process to be the best break-even point for that.

[@raunop7391]

You don't have real cold and using 300mm? And shouldn't you use XPS in the ground? I have test pieces of EPS and XPS in the pond. I have to make a video, hate to see using EPS in the ground...

[@TrogdorBurnin8or]

Thanks for the rec on the termite-proof membrane. Subbed. 7.5 psi is not a lot on that Rockwool. I _hate_ the idea of foam everywhere on multiple grounds, but you do get it 25psi and up, and it does displace water to a great extent. The (fairly expensive) rockwool doesn't insulate anything if it's saturated with water; Are you fully confident in your subslab drain tile? Fiberglass or basalt fiber admix helps a lot with surface chipping and small crack propagation, but supposedly it doesn't do much at all for large cracks or ultimate strength in bending. Hydraulic press tests of beams show the same ultimate strength, but the admixed beam looking a lot better at just below that failure point. Unreinforced slabs get stronger against loads as the square of their thickness or better. At 2" you are only making a quarter the strength of a standard 4" slab; Some people won't build less than 6" (9x as strong as yours) or 8" (16x as strong as yours) unreinforced. If a client takes one of these - www.homedepot.com/p/Husky-90-in-H-x-90-in-W-x-24-in-D-5-Shelf-Welded-Steel-Shelving-Unit-with-Wire-Deck-in-Black-ERZ902490W-5/206813267 rated for 7500lbs spread over four small feet, and loads it up to capacity, that may punch right through this floor, either at the feet or around the whole area. Concrete doesn't like to bend much even with fiber admix, and to support a load of 7500lbs you need 1000 inches of rockwool (7.5psi) multiplied by some factor for how elastic things are. That's assuming your concrete is going to cure correctly at these temperatures, even if we see wild swings week to week. I don't know enough about the process to say, but concrete contractors tend to be very wary of this stuff at this time of year. The price negotiation POV you're taking is fine if you're sure that you're dealing with a certain type of contractor. Any other type of contractor will find it highly exploitable. The way to fight that tendency is to get multiple fully-burdened quotes and/or to know who you're dealing with from past work.

[@AM-fu1kq]

It's not a standard slab. In the video he describes that it's a rat slab. Nothing goes on it. There won't be enough height to put shelving. It's only used to maybe house ducts, maybe water pipes. There will only be a contractor from time to time, so 2" is good enough.

[@TrogdorBurnin8or]

@@AM-fu1kq Ahh, that makes a lot more sense.

[@HomePerformance]

All good thoughts, Mr. Burninator, and Andy’s correct, it’s just for aesthetics and rolling around on

[@MHICle8u1F]

Hello

[@HomePerformance]

Hi there

[@karenromero1703]

Why is rock wool insulation better than a poly board insulation?

[@HomePerformance]

Different properties, that’s all- there is no silver bullet product in any home. When we filmed, there was no foam insulation that didn’t have flame retardants making up ~10% of its weight. Those would have gone into the soil in our garden and up into the house (through the vapor barrier).

[@lincolnmarkman]

Compacted soil, dirt is what you sweep out of your garage.

[@HomePerformance]

Soil means topsoil to geotech converations, I mean inorganic, good old dirt

[@sladeoriginal]

seems very common that concrete trucks show up with wrong gravel, poor slump, or additive not added.

[@davidbradley3074]

Always always always do a slump test, 3 day and 30 days sample test.

[@stephenjdixon1]

just wish he would get on with it

[@HomePerformance]

Try the fast-forward button, buddy

[@inspirepics]

You are unbelievable a true pioneer. Yes this is an investment and of course it is a costly one. But you have grasp the exact way on how to achieve a great build by making every trades man work to there very best. Show respect and get respect and I know the trades will probably take care of you and save you money in the long run. Take a bow my good man. 👍🏻

[@HomePerformance]

Thanks brother!

[@SimonKentucky]

That Rockwool board is water resistant but not waterproof

[@HomePerformance]

Sure, it's important to try to keep water off anything we want to work

[@kylekeeler104]

This is closer to standard rather than "high performance" these days

[@GreenIllness]

3:40 Lol, no way that sheet is 15 mm! You probably meant ".15 mm" or else myself have been using the term "mill" completely wrong.

[@HomePerformance]

Mil actually means thousandth of an inch. 15 mil is .015 inches thick.

[@GreenIllness]

@@HomePerformance I had no idea! I thought it was short for millimeters. Thanks

[@HomePerformance]

👍🏽👍🏽

[@canonicaltom]

If you don't want to negotiate a price, you should still be willing to say no if they try to overcharge you.

[@lewisdoherty7621]

Too bad the radon won't kill off all of the termites.

[@HomePerformance]

That would be a much more elegant system

[@MolotovWithLux]

#requirements

[@Homeairquality]

Wear a respirator when working with rock wool. Nasty for the lungs

[@HomePerformance]

Safety first, but outdoors and with the rigid boards instead of batts, it's a lot less of an issue

[@brassmule]

Shouldn't you be wearing PPE while handling Rockwool? It's rock which reminds me a lot of asbestos - certainly not *as* dangerous but still a hazard to breathe in, no?

[@HomePerformance]

Outside, not such a problem while we make a quick vid.

[@xephael3485]

No drains or tile in slab, bleck...

[@HomePerformance]

What for?

[@xephael3485]

​@@HomePerformance Well besides the fact water generally finds the lowest point...they're useful. Easy to tie into foundation drainage system. You made a bathtub without a drain.

[@HomePerformance]

Understood, but our sewer connection goes out the foundation wall. Also, no water once we close it in and roof over it.

[@xephael3485]

@@HomePerformance Unless a water heater or some pipe decides to go south...or there is a fire and they pump a bunch of water into the building. I like things that can drain without assistance. :-)

[@HomePerformance]

@@xephael3485 I agree with you, but practically speaking it was just not worth the extra effort. There will be nothing on the floor of the crawl, and pumping it out will be a relative piece of cake.

[@WAJK2030]

I can´t believe you are putting NO waterproofing below the fibre insulation. I mean the insulation bridging with the foundations is one thing, but this detail is just wrong. The rockwool will soak by time and therefore be useless. :O It would be different thing with PS or Glassfoam gravel.

[@HomePerformance]

Johann, 6” of gravel underneath. It’s ok.

[@HomePerformance]

Since it’s outside the insulation, we don’t mind convection

[@HomePerformance]

Insulation doesn’t stop heat flow, it only slows it down. Something will always be taking the heat coming thru- wind blows, ground gets snow on it, etc.

[@patrickeh696]

Not a good idea to put in a crawl space. Creates more future problems that is might solve.

[@HomePerformance]

Haha- it’s actually not a good idea, cosmically speaking, to build a house at all. It will some day be destroyed. All of us will die someday too. But to your smaller point, this crawl will perform perfectly- look further into our design webinar on this channel.

[@bahopik]

No arguing? You should be like the owner of a job I'm working on - ask for 50k in change orders, approve it, wait till it's done and then pay 7k

[@HomePerformance]

Sorry to hear that buddy

[@DoorPro3667]

Rockwool does NOT insulate when wet. Put the water barrier under the insulation, or better yet, use insulation that does not absorb water. SMH

[@HomePerformance]

The rockwool can NOT be sitting in water, due to the Form-a-Drain system. Good idea tho.

[@DoorPro3667]

You are insane if you think drain tile will remove ALL subterranean moisture! The rockwool will act like a sponge. I pity your customers...

[@HomePerformance]

Rockwool is hydrophobic. It does not act like a sponge. Try again my mans.

[@ab-qn7kv]

I don't agree about discussing budget with your subs. Do you recommend getting multiple bids? If so, do you not discuss the price range of those bids with the contractor you find most competent? Price should have nothing to do with a contractors quality. A true professional will put their integrity, quality of craftsmanship, and punctuality of timeline first. Having a conversation is not haggling and if a contractor agrees to the terms and your due diligence has led to them being the most competent for the job, then they should follow through accordingly.

[@andrewblack7852]

The kindergartener walks into the class with a camera and makes 300 you tube videos... the days we live in. Novice experience level teaching... not that he is inarticulate, he is articulate. Not that he’s foolish, he is a bit. But it just reminds me of mark zuckerberg telling Jerry Seinfeld that he bought a... “bicycle “.... and he’s learning to ride it.

[@HomePerformance]

Wow, andrew, quite insulting. I hope you don’t talk to your wife or mother that way. We are all kindergarteners in most ways, and if you really think you know your topic perfectly, I’d say you might be the novice here.

[@terrybrown5883]

MATT Reisinger and associates all are Great Help