Insulated Concrete Forms - Overview, Costs, and Cons

on the build show today we're talking about insulated concrete forms what are the benefits how's the system work what's it cost why would you use this over traditional construction methods and even what are some of the downsides let's get going on the build show today we're gonna dive deep into ICF construction that's insulated concrete forms now today's video is not sponsored by an ICF manufacturer but there's a bunch of players in the marketplace I've actually done some belt X ICF before and my job sites there's an Vic build blocks several others I don't even know all the names because there's so many players we happen to be on a build blocks job but today's video is not sponsored by them now what is ICF all the manufacturers have a slightly different system but basically it's a foam Lego block that gets filled with concrete in the center that that's the short way of saying it if you look at this foundation behind me what you see is we've got a concrete footer and then the blocks are laid up on top of that they're very lightweight it's very owner builder friendly and in fact this owner one of the big reasons why they chose ICF was because they wanted to provide the labor themselves we're gonna get into the cost in a minute but what you see here is those blocks are laid up just like a Lego set they're hollow in the center so you're gonna lay a grid work of rebar as you lay those up and then you're gonna pour concrete into those cells so in effect you've got a sandwich with EPS foam concrete an EPS foam okay so if you were doing ICF for just the foundation this is what it would look like you'd have the basement walls this is a ten-foot wall right here and you would pour it up to here and this would actually flush out with concrete so that your mud so would sit on top of this and then you go wood frame above but in fact this is the front entry porch for the house and we're going to store two stories with ICF so here's what we're doing here we've got this block that's l-shaped right here and then we've got a series of rebar coming up and then actually we're gonna have a poured concrete deck that's going to integrate here that's one of the intricacies of ICF is you need to figure out how you're going to attach your floor system and this decided to do build blocks system I'll put a link in the description below kind of a cool system where they've got a poured concrete floor integrating in here and then they're going up from there but this is a great place to kind of see how it works you've got concrete filling the cell so you've got approximately a six inch continuous concrete wall no breaks on there you've got a series of rebar that's laid in and you can see there's some cages in there to actually fit the rebar and you've got a horizontal and vertical grid now he's got a mixture in here he's got number four and number five bar if you're if you're familiar with rebar spacing a number four bar means four eighths so this is basically a half-inch bar in these verticals you see that are a little thicker this is the number five bar or five eight seven of an inch rebar this is in a grid network so when the concrete's poured this is a super strong wall and the form boards which is this - I think it's two and a half inch EPS foam on the inside on the outside which holds the concrete in place stays and so now in effect you've got a continuous insulation on the outside of the building and a continuous insulation on the inside of the building now one of the questions that you always get when you start thinking about ICF is how do I attach to it now build blocks has a pretty interesting system and similar to a lot of manufacturers they've got a inner core here made of plastic I believe this is polypropylene and inside this block right here there there's actually a grid Network and if you look on the block itself let's see if I can scoot down here and show you they've got this grid tied network here that anywhere you place the screw along here you're gonna have polypropylene that you're gonna be able to screw into and then you've got these special what they call hard points everywhere you see this Bibi on the block right there that's gonna be an especially hard point and hopefully I got the numbers right but anywhere you screw in basically you've got a hundred and fifty pounds of screw hold and where you've got the BB you've got like four hundred some pounds of screw hold at that location I actually tested this yesterday because I was curious how much it would hold and what it was like to screw a screw into there so I made two two by four block cut him on an angle on the table saw so I could grip him and I'll tell you what I didn't put those in hard points I put those just into the grid and I was able to hang on those no problem no movement which means that hanging sheetrock on the inside hanging furring strips and some hardiplank siding or attaching other materials you're not gonna have any problems this is a very rigid screw hold next let's talk about the how how's the process work so basically first we're gonna be pouring a footer for the entire building and that's this right here this footer is gonna be the base plate for the house and then once the footer is poured there's gonna be a keyway with rebar that sticks up in these foam blocks lay on top of that now one of the beauties of these blocks is look at this super lightweight and they snap together and hold together very cool and and because they're so lightweight this tends to be very owner builder friendly so if you're thinking about building your house and you want to do the labor I think this is a very interesting system because of this extreme lightness now once these blocks would go up the biggest thing that you need to do in or one of the most critical things I should say is internal bracing now one of the things I like about this system in particular is they can be braced fully on the inside as you can see here we're on the kind of uphill side of this walkout foundation on this house so at this portion of the foundation we're gonna end up being underground by seven or eight feet and having to brace in here would be really hard so one cool thing about this system and I'm not sure if this is unique to build blocks or other ICF guys do this as well but they can brace just on one side so there's braces on the inside they're gonna be secured to the ground and then because we've got these channels of polypropylene we can screw into there gonna put that you shaped brace on there and then they're gonna use a screw tightener to get this vertical wall plumb now this is something that's critical for an ICF foundation well you've got to make sure that our footer is totally dead level because that's our base to put these blocks on and then once we do that we need to absolutely make sure that this wall ends up plumb now I understand that I see F people and I don't have this from personal experience but as kind of reading on this topic some people actually tow in just a little bit meaning that this this wall itself when it's framed might actually tilt inward towards those braces by something like a half inch or so because on poor day the last thing you want is this wall to be out of plumb and you're having to pull it back plumb and the other thing we want to make sure is that we've got a perfectly plumb and level surface if this thing gets poured and it's out it's a bear and trying to fix that later or make it look right later is really a problem and the other thing we need to be really cautious on is blowouts so do your bracing correctly and do your research when it comes to that if you're thinking about doing ICF okay why choose ICF I think there's three main reasons disaster resiliency energy efficiency and sound let's start with energy efficiency now these walls yield an r22 when it's all completed remember we've got two and a half inches of foam we've got a continuous concrete wall then we've got another two and a half inches of foam now our 22 on the surface doesn't sound like a lot I can get an r22 out of a 2x6 wall frame traditionally but what's the difference the difference is I've got that foam continuous all the way around the outside of the house there's no thermal bricks every time I put a stud in the house and then insulate in between those I've got a huge thermal break that stud only has a couple of our values maybe in our value three or four whereas this is gonna have that continuous insulation all the way around the other thing is we've got this massive concrete in between the wall there here's one of our blocks so remember we've got this insulation on the outside it's totally continuous we've got this continuous concrete wall and then we've got another layer of foam on the inside so that our value doesn't totally tell the story if you go to the bill blocks website who happens to be this manufacturer they say that it's more like an effective are 40 now you have to take that with a grain of salt but I think there is something to this you've got this thermal mass right here with this concrete then once it gets the temperature it doesn't want to change in a hot climate think about that the Sun is heating up the outside and this concrete mass here wants to stay the same temperature we do it's gonna resist that heat flowing into the building similarly in a cold climate it's gonna resist the heat loss through the building because we've got that massive concrete wall now as we're talking about that concrete wall I think that's one of the big selling points from me on ICF is in effect we've got a concrete house a very insulated very airtight but concrete house in the disaster resiliency I think this is really a reason why people chose it and in fact that's why this homeowner chose it they wanted to make sure that when that tornado came when that storm comes when the winds start whipping up they're not gonna have an issue with the house moving and with a six-inch concrete wall like this with a rebar in it I can tell you this house is not going anywhere ICF houses really should be in the hundreds of years when it comes to how long you would expect a house to live when it comes to this type of construction that concrete wall is massive it's not going anywhere okay so what are the situations where then ICF works if we're talking about disaster resiliency I think if you're building coastal where you've got storm surge you've got other big issues with coastal environments that's a great place for an ICF wall I think also if you're at a tornado alley for sure this is a great system to use a tornado is not going to affect this you're gonna have to really anchor your roof down but these walls are not going anywhere I think also fire zones is an interesting topic this EP is foam that's on the outside has a 15 minute fire rating there's a retardant on here but generally speaking this foam is not UV resistant we got to cover this and we're gonna cover this with masonry we've got a brick ledge right here as homeowner is gonna do basically a stone or a stucco facade on the whole outside so then we're gonna have really good fire resistance the other thing that I think is interesting as we're talking about that resiliency is because you've got the those polypropylene studs let's call them inside here that can hold just as much holding power for when it comes to a screw as a 2x4 would if I had a flood let's say on this house we had hung sheetrock to the inside when that floodwaters receded we could pull that sheetrock the EPS foam is not gonna absorb any water the concrete's gonna be totally fine there's really nothing to dry out it's not gonna go anywhere this house is gonna be solid and we could remodel this really really easily after a storm or a flood situation so that's a big benefit of this as well the last thing I want to mention was sound you know that's one thing I hadn't honestly thought about until I came to this jobsite they told me the STC rating on this wall is actually a 54 that's really high that means that if someone's yelling on the inside of this wall I'm not gonna hear that on the outside and it's not as much the EPS that's doing that it's really that 6-inch continuous concrete wall you're not gonna hear a thing through that what about cost I got some basic numbers from the guys that build blocks and here's what this is breaking down to for each wall square foot it's about five dollars in materials and then for the labor to install those blocks to basically put the Legos together and to pour it another five dollars a square foot so we're talking about ten dollars in materials and labor but then we need to add in the cost of concrete which of course is very is varies quite a bit right now where I am in Texas were about a hundred and twenty some dollars per yard of concrete which means that we're about another five dollars per square foot for concrete costs so all in we're about fifteen dollars per square foot now remember again that's wall square footage and not floor square footage so for this particular house to give you a few numbers this house that you're seeing here is about a 3,000 square foot basement in about 4,200 square feet above so we're about seven thousand square feet but the wall square footage I'm told is about 9,000 square feet on this house so you can do the math yourself but one interesting point on this house is that our owner over here is a younger couple they're about my age they've got two kids and one of the big reasons why they chose this is because they could do the labor themselves and in fact they were able to buy the bill directly from the manufacturer not everybody lets you do that in the ice F world so in effect they're gonna end up saving about five dollars a square foot bringing the cost of these walls down to maybe $10 a foot installed very cool the other big reason these clients did it on this site is because the power company was going to charge them 40 grand to bring in a power line for this house and that kind of got them on this road of gosh if I'm gonna build an off-grid house rather than spending 40 grand on electricity I could spend $5,000 on a battery bank another maybe 10 or 15 on a solar array and for half the cost I could have a house that doesn't even need a connection to the grid and then the fact that they could build it themselves this is a really interesting project okay lastly let's talk downsides you know when you get into the ICF world and you look at online reviews or you get onto sites like green building advisor and you start talking ICF there's some people talking about ICF that it's basically a religion that they are trying to convert you and they think ICF is the only way to go in you're an idiot not to build with ICF but what are the downsides what are the things that you may want to think twice about before using a system like this I think there's several costs certainly plays a factor it is more expensive than a traditional system I think low our value ultimately is a bit of a tractor as well we're outside of Georgia so I think this wall is going to perform incredibly well here but this same wall in a really cold climate and climate zone five or six let's say if you're building in Minnesota I tell you that I'd want to see more exterior insulation on this I'd want to see a block that you could add a couple of extra inches of EPS on the outside of the building to yield a higher r-value because I can build a much higher r-value ultimately than this at a lower cost disaster resistance though I mean that one's hard to that's hard to to say a downside on I think this building could get hit with serious storms crazy events earthquake fire and it's not going anywhere that's that's a big one on this project another downside though you need to think about is remodeling and additions you know you think about this big box right here we've got these window open that were formed and then poured if I wanted to punch another opening in this and add a window here oh man that is not an easy job even just breaking out the concrete saw and getting an opening and then waterproofing it anytime you think about remodeling your auditions with ICF it's gonna be a bear so you better have a plan that you like and they don't mind sitting there for the next couple hundred years on your property because this would be a really hard house to remodel the next downside I want to mention is making sure that your walls are perfectly plumb and level I mentioned that earlier in the video but honestly I think that is a downside to this system especially if you're an owner builder you're trying to do this yourself you better brace the heck out of your building and really ensure that on poor day you've got everything ready to go because once these walls are poured if they're out of plumb you've got a nightmare in your hands it's a real pain and I know lots of builders that have done an ICF project and don't continue with it and it's because of some of those downsides but the last downside that I want to mention which also is a critical one that I don't see talked about a whole lot on review sites is waterproofing and I think that's because you've got a lot of first-timers building they haven't done this before they don't know how critical the waterproofing is on a project like this you basically have miles of cracks when you've got an ICF project because those Lego blocks are coming together and you think that because you've got a concrete wall there you're not gonna have any problems with waterproofing but in fact there's lots of areas that it's tricky to waterproof and especially openings to think about all these window openings and how do we waterproof that and when we've basically got a foam block with a buried polypropylene stud in there not super easy to waterproof guys thanks for joining me on this video I know there's a lot more that could be said about ICF hopefully we'll do another video series in the future about this but stay tuned for our next episode work we're actually gonna be talking about the waterproofing as I mentioned earlier and we're gonna be talking specifically about this system from our friends at poly wall and then we're also gonna do a video on the drainage system that are doing for this house and I think it's interesting in the the waterproofing we're doing here and the drainage we're doing here would also work for a standard concrete foundation so I think those are gonna appeal to you whether you're building ICF or not guys follow us on Twitter Instagram hit that subscribe button below we've got new videos every Tuesday and every Friday otherwise I'll see you next time on the build show [Music]

Channel: Matt Risinger

Views: 851,702

Keywords: polywall, icf, insulated concrete forms, build blocks, bautex icf, what is icf, foam lego blocks, concrete, foundation, concrete home, concrete blocks, icf building, icf cost, what are icf blocks, pour concrete, icf foundation

Id: MRipzKkeQik

Length: 18min 30sec (1110 seconds)

Published: Fri Sep 21 2018