Great video. I am a builder/inspector in the rocky mountains, and I see a lot of sealed, or "conditioned", crawlspaces. Around here it is almost always done with closed cell spray foam, vapor barrier and insulation all in one. Nice to see another way to do it, thanks!
In Japan a sealed crawl space with concrete floor and spray foam walls is the standard, continuous mechanical ventilation with heat recovery is required by code. We get -6c and snow in winter, 32c 80% humidity in summer.
As a PNW contractor I have been pushing for better building practices like this. He’s right this is less than 1% of builders in our area thankfully I build in the high desert part of the PNW and we have a very dry climate no need for de humidifiers wood will not rot or mold around here unless in contact with soil. This assembly is perfect for my area.
In my house here in NY I went from a vented crawlspace to a closed one. I am super happy with how much better the floors feel in the winter months, they're not cold anymore. I used polyiso instead of rockwool.
Think you missed an easy opportunity on your mudsill installation for a high-performance home. Look at Steven Baczek's mudsill detail - he layers foam btw a top and bottom layer of (non-hardening) accoustic sealant, which acts as an air barrier (and a critter barrier) - simple, cheap, effective. Glad to see a conditioned crawl space - the owners will really appreciate it - better air quality/lower moisture/no bugs/critters and stable substrate for wood flooring since all spaces will have equal moisture content.
I like seeing the different products that you guys are using that are a complete system and not available where I live . The zip system and the floor sheeting look excellent. Awesome job , and series
It's really interesting, that you have a completely different approach in the US, than we have here in Europe (in Hungary, to be exact). We put the insulation outside of the concrete foundation, as the concrete itself acts like a huge thermal battery, and also conducts moisture. So we insulate it from the environment.
That's more common here too. I build these sealed crawl spaces all the time and we use ICFs so there's insulation inside and outside of the concrete. Cold climate.
Do not repeat this at home. They do not know what they are doing . Look, they put 4 in insulation on walls but they left footing totally uninsulated one or two feet of soil will not stop heat from escaping that crawl space. They should have done at least 3 more feet of horizontal insulation inside of the perimeter of those walls
There's always a conflict between wanting the concrete to serve as the extremely strong and robust outermost layer, and wanting it to be inside the thermal envelope for the thermal mass benefits. I'm pretty sure it's not physically possible for the same lump of concrete to do both.
Very cool system of sealed crawl,you have to look at time saved in the schedule ,longevity of the home. The only negative is a big rain event creating said swimming pool before the lid goes on. Have been installing titans since 04' ,for plated fence posts . The best part is if you need to remove one,you simply blow out the hole and fill eith sealant...unlike a wedge anchor the needs to be cut and ground down below concrete, and then try to seal around thr threads.
Hey, Timmy. Great video as usual. Just a clarifying question for you. Your brother seemed to be saying that the sealed crawl space is unconditioned. Since the insulation is around the perimeter of the crawl space and there’s no insulation between the floor joists, isn’t it by definition a conditioned crawl space even though there’s no source of heating and cooling in the crawl space? Kind of like putting a shelf or tray in a cooler with the ice on top of the tray. The food below the tray is going to stay just as cold as whatever you put on top the tray because it’s all inside the insulated enclosure. Looking forward to what your testing shows when the house is complete and what that will mean for future projects.
I'd call that semi-conditioned. The temperature is going to be somewhere between room temperature and soil temperature. But so long as the humidity is controlled, it should be okay.
I've been wondering about this assembly for a while. People build sealed crawlers w/ rigid on the walls in warmer parts of the country, but I'm not sure about here in western WA where the ground temp averages 50-55F year round. Wouldn't that mean that there's a 20 degree variance between the crawl and first floor, so you're effectively paying to condition the crawl as well, even if it's only a few degrees? Also, this is a low(ish) radon area, seems you'd still want to do something like mech ventilation (and now you have incoming cold air), or maybe the heavy VB is enough? Certainly the VB will help with moisture vapor, which is really a thing here over time. I toyed with doing this kind of assembly a couple of years ago, but after much debate we gave in and did a normal vented crawl. I would very much like to see longitudinal data on how this assembly performs over time. Great video, thanks for putting this out there!
Great questions. We'll be showing how we are addressing Radon in future videos as well as the dehumidifier installation. I'll try and remember to address your question in a video regarding the difference in temps. Basically the crawl won't have a difference in temp than the house in an appreciative way. I want to get an expert to talk about that on camera. Just need to find the right person 🙂
You could possibly work out a deal with Rockwool to see if they need any framing done at or around their factory and maybe you'll get a tour along the process as a plus. Hahaha
Awesome video. Love seeing the details. If not conditioned/balanced through the HVAC primary system, how do you plan to control humidity in the crawlspace? Dehu?
Man, still wishing you’d come down to the Gorge and build for me. I’m starting my ICF garage project next month, if you’re ever down near White Salmon give me a holler! I’ll show you some locals only spots, and you can critique my work based on my learnings from you and Matt 😂
I was stuffing rockwool at the Bell Street pier in the early 90s. Its the nastiest material I have ever worked with. Big chunks of spun Californian red glass. The splinters of glass, Im still picking them out 😂
Concrete will always be a better weatherproofing material than timber. So it just makes sense to seal, insulate, and condition your crawlspace, rather than trying to seal and insulate the underside of your floorboards. I will never trust the waterproofing and vapourproofing of the crawl space, but that's very easy to fix with a little dehumidifier to make sure of it.
I’m curious about the floor insulation code. I believe it’s r-30 for the new 2021 code? How is that the r-16 comfortbatts satisfies this requirement? Or are you using the basement codes for vertical walls and then add insulation under the vapor retarder? I really like this detail and hope to incorporate it into a remodel here in snohomish county as it seems it would make a walk out patio easier to design without working around Crawlspace vents
Great question. This is vested under the 2015 IRC with WA Amendments and WSEC. Vapor control is covered in the IRC while thermal control is governed in the energy code. We treated the crawlspace essentially as a short basement, but they aren't identical (eg, not liveable space, no concrete floor). There are different r values prescriptively if the insulation is inside or outside. I recommend detailing the design and submit it to your AHJ. If you've thought through your control layers and applicable codes, hopefully, the code official will sign off on it.
QUESTION: why are mudsill gaskets/foam no good? you mentioned that a foam mud sill gasket wasn’t useful and that the borate treated wood on concrete was fine. All I’ve ever seen are people rolling out a length of pink sill gasket prior to installing the mud sill.
Good question. Sill gasket isn't required in the code with treated wood. We also don't need it as a "capillary break" because even though water can wick vertically through concrete, the reality is, it doesn't. This has been demonstrated in tens of 1000s of homes across the country over many decades. We are going to seal the Zip to the wall with Siga Fentrim and that'll provide airs ealing at that connection.
I always thought it was more for bugs. Stalinlop I think is the channel name. Really good Latino framers. They use copper sheets. Wonder what the pros and cons for that are
@@davegordon6943 the copper sheet is called a termite shield. It's definitely required on block walls because bugs could be inside the cores and get into the wood framing without a sign on the exterior. The point of it is to force termites to make a mud tunnel over the exposed copper so you can see them getting into the wood framing.
ICF is a joke and the cost just tells you how good the salesmen are. Crap product making a crap wall. The only reason they exist is that people don't know anyone can rent commercial concrete forms. Go look at thermomass if you want a high performance wall. ICF is the construction con of the last 20 years. Pros don't use it for a reason.
Great video. I have been thinking to use this type of system and this is helping to answer my questions and concerns. I have been wondering with a conditioned crawlspace, who goes down there to clean when the dust and mold spores settle in? You can't recirculate that air back into the rest of the house!
And yes free labor is expensive. It takes about 9 months for me before a new hire makes money on a shift and then starts paying back the first 9 months. Take advantage of his offer. Plan on offering to work for free until someone decides to pay you. Then don't complain about getting minimum wage because other wise it would be months more before you would get the low rate to get hired.
Honest question, is there a possibility that water could get into the extra 1/2" depth of concrete holes you drilled and freeze (before joists, decking, etc) go up
I'm sure its a possibility, but the washer on the Titen tight to the 3x3 plate tight to the mudsill, I'm going to say I'd be very very good money zero water gets in there.
@@AwesomeFramers For people who dont know, when I was bridge building, we used Titans to secure pick points on deadmen (9,000 lbs+) and were able to lift those deadmen without a problem
Interesting question, I don't know I bet it would be very cost prohibitive and the benefit would be very slight. Running it this way is crazy fast and then we don't have to insulate between the floor joists.
problem with foam is it is extremely flammable and puts of a very toxic gas when burned. I used rockwool in my house , insects dont like it and rodents dont like it. Very water resistant and fire resistant. by far a better product and less expensive that foam.
Wouldn't it be a good idea... in Tornado Areas, to have Tabs on Both Sides of the Washers to Hook a Cable that goes over the Top Plate of the Wall to give some greater Ability to withstand High Wind / Tornadoes better. Because your bottom Plate will Never go anywhere, But the wall can just fly away. Amazing Strength with the Titans. But it would be a Great Opportunity to Transfer that to the Top of the Wall... Just Some Thoughts.
Certainly a very honest debate about house insulation and build practices. I don't think we are really improving things with these high tech sealed house products. If your energy was free, such as thermal, solar or wind, then standard breathable houses would be cheaper and healthier.
@@AwesomeFramers houses in which opening a window or door doesn't make your whole purpose of a sealed house redundant and you can just enjoy natural breezes.
@@AwesomeFramers Thats my point. Why do you want to filter the air to such a degree? Do you intend to live in your house 24/365? The cost to create a leakproof home that will actually last as a leak proof home doesnt seem to stack up.
@@worldadventureman It is far better to control the air than leave it up to leaks. Outside air is often full of pollution, e.g. wild fire smoke, car pollution, yard equipment, etc. Filtering the air is better for those with puliminary issues, not to mention it is more energy efficient. By building tight and venting right, we get healthier homes and more comfortable occupants. Those same occupants can always open their windows and doors, but your homes can't manage and filter the air. My wife worked sleep and pulm for 13 years as a nurse. Those that deal with pulmonary issues are greatly impacted by air quality and they need a place they can be comfortable. I bet you've never set up an indoor air quality monitor in your leaky house. You will be shocked at how bad it is.
Surely the marginal cost of going from a crawl space to a full height floor isn't a large percentage of the build cost in a modern home. I'm not sure why people still cut that corner. Like, if you can afford a mountain top manor made with rockwool, then surely you can afford another floor in either direction?
How is it a "cut corner"? This house plan isn't designed to have a basement. Adding it would cost 20-30k more on top of record high housing prices. We aren't adding it for the same reason we aren't installing gold plated faucets and an indoor basketball court 😁
That's housing. If you pitch a tent you're fighting nature to make it not blow away. But if you watch birds and ants and bees and any other animal that makes a nest, they're fighting nature too, constantly repairing and maintaining their homes.
@@tealkerberus748 yeah but this type of house literally needs electricity to not get musty and mold out... Whereas traditional methods can be left unattended for decades and as long as the roof holds up it's good to go
@@ThaFKINman Traditional houses work .. except when they don't work. And then people get horribly sick from breathing mould spores that shouldn't have been there because they thought their house wasn't going to do that to them. Whereas with an actively ventilated house, you know if the power's out, and you know when it comes back on. If you leave your house empty for decades you deserve to lose it to squatters anyway.
@@tealkerberus748 but your referencing an improperly built house lol.. a traditional house built with proper ventilation would have zero issues being left unattended. The fact that you think the homeowner's deserve to lose their house if they don't pay the electric bill and want to leave it vacant certainly does not make it a better option either lol
Awesome video. Love seeing the details. If not conditioned/balanced through the HVAC primary system, how do you plan to control humidity in the crawlspace? Dehu?
