14 Tips For Building an ICF Home -- Improve Your Chances of Getting it Right!!! 

only thing i would add is a very sharp industrial sized exacto knife is perfect for cutting ICF. No need for a hot knife unless cutting horizontally

Excellent tips!!!

I'm so happy to help!!!

Glad to help

You're welcome

I'm glad this will help you out. Good luck with your build!!!

I hope it helps

He loved being on site. It always amazed me that he could sleep with all the noise around.

You're too kind!!!

@@Challenged1 : these are practical limitations. will be very helpful to plan stuff and not to reinvent the wheel of you are doing diy

You can do it, and it's worth it!

Glad it was helpful!

Good deal. I wish you luck with your build!!!

I sure appreciate it!!!

I've made a bunch of ICF videos which might answer most of your questions. Check out my channel page to find those.

You will love it!!!

sounds like my problem , ICF gives greater flexibility in design but contractors and inspectors have years of stick frame knowledge and in my area very little on ICF. Trying to get a contractor to build greater than one level basement is causing me problems and I may be force to go stick frame on my 2nd level.

Thank you for the kind words

Thank you. I didn't and I'm not sure my local jurisdiction would have allowed it at the time of my build. We have highly expansive clay soils, so I'm not sure I would have used Helix in the basement pour anyway. Keep in mind that the rebar helps hold the walls together during the construction process, before concrete.

I think they would be great with engineered lumber. Stock lumber just doesn't stay straight long enough

I put horizontal rebar on every row, which means each row gets built separately.

Excellent, thanks for sharing.

My house is so big, the spans are too long.

What sorts of info are you looking for?

@@Challenged1 I live in Florida and we have two issues that Im not sure are as big of considerations for ICF builds in Kansas so I was just hoping for your point of view. 1) Does Kansas require termite inspection for final inspection prior to certifying the finalization of the build? 2) Are termites a major consideration in Kansas builds? (If Yes) Was it difficult to get a company to treat and certify the build prior to final inspection. 3) Humidity is also an issue we have in Florida. What are the humidity levels that you experience in your area? 4) Do you have issues with your build in regards to humidity? These are just some of the common issues that I hear from other builders and was hoping to get insight from you. As a fellow engineer, avid DIY'er, and real estate enthusiast I think experience is valuable as insight and you obviously have first hand knowledge. Thank you again.

@@beaubailey3671 1 & 2 - No termite inspection necessary in Kansas and haven't had anything treated. Termites can and have been an issue at some of my other homes, so it's something I'll keep an eye on. 3. Kansas isn't as humid as Florida, but it is pretty humid. Most mornings dew in the spring and fall, and many do in the summer as well. 4. In my opinion, ICF is going to have humidity issues the first couple of years. Size the HVAC units right, use an ERV or HRV, and run dehumidifiers, and you'll be fine. I have noticed a substantial drop in the interior humidity of my house from year 2 to year 3.

In UK the codes require a 1 metre (40 inch) deep foundation and often more in clay soils. Messy and costly on labour and concrete. Screw piles under a ring beam foundation are often a better option but still quite rare in UK.

The more effort you put into the design, the faster and cheaper the house will be. Yes, it's worth your while.

I think a 2nd pair of eyes is never a bad thing if it makes you feel more comfortable.

Yes, 2x4 braces on the inside of each buck is required. No, I don't think the primer protects against UV. It's just nice and sticky. Like you said, the concrete lintels would be overkill and an added expense that isn't necessary.

Good idea

I ran 1 #4 bar horizontally every block (16") and 1 #4 bar vertically every 16". You may be able to space the vertical bar a little further depending on your building codes, but I tend to over engineer.

I don't have any experience with them

Should be foam and then vapor barrier. I did it wrong in real life.

@@Challenged1 thnx for the update. Started today my footings. ICF BLOCKS incoming..... :)

@@darinjuliesims354 Good for you and a big good luck with your project.

Thanks!!! Other than the excessive moisture during the first year or two, no real problems to speak of. Any out of square problems that I had were my own fault, not the icf.

Any furniture placed against the walls would be best protected with plastic sheet until the walls have dried out. Check it regularly for mould. Permanent fixtures like kitchens might be best left until later but certainly use a poly sheet barrier behind the units.

I have two 4" fresh air ducts. I don't have a mechanical ventilation system.

@@Challenged1 oh wow, and thats enough? What do you have, one duct per level? Everywhere I read, the ICF "experts" seem to suggest that an HRV/ERV is 100% necessary for a healthy ICF home.

@@joshuabeemer4062 Fresh air is 100% necessary, but an HRV/ERV will thermally transfer heat, saving money on that fresh air. It's a highly suggested addition to all of the other energy efficiency upgrades.

@@Challenged1why did you elect not to go with an hrv/erv Sir?

@@joshuabeemer4062 At the time it was cost.

You won't be able to build it fast enough to do this method, nor will you be able to keep the wall straight and plumb. You want to keep as few cold joints as possible, so it will always be better to stack the full wall, and then place the concrete.

Yes

How much extra are they charging in your area for fly ash cement? Stronger, flows better, just takes longer to come to full strength. Plus a waste product from energy production

I used it to bend all the rebar.

@@Challenged1 Thanks.

@@Challenged1 I saw a video where an additive was used instead of rebar. Have you heard how that works?

@@robcharles3363 I have heard of it, but not anyone that has actually used it. You would need to make sure your local jurisdiction is okay with it though.

@@Challenged1 thanks

Menards

@@Challenged1 thanks

My jurisdiction did not require an engineer's stamp, however, I'm a licensed engineer, so mute point. I used 3500 psi concrete as I prefer to over-do everything. I used #4 bar horizontal on every layer of block and #4 bar every 18" for vertical. One thing to know if you are using 6" or smaller block, use a 3/8" chat mix for concrete. Your supplier will know what that means. The larger aggregate of a traditional mix will get caught between the block and the rebar, and consolidation will become difficult, especially around/under windows.

@@Challenged1 ⅜" aggregate still seems pretty chunky. I've never understood the benefit of chunky aggregates. I never looked into it, but I wonder if just using sand, with no gravel or other aggregate, yields stronger concrete. For high strength concrete, I'm thinking about 6,000 psi to 10,000 psi - 3,500 seems very weak to me, not significantly different from 3,000. I've been reading up on the research, and all the advances over the last 20+ years, and I'm impressed with what the different pozzolans can do, fly ash, silica fume, etc. And Energetically Modified Cement, which they've been using on some highway projects in Texas. The ceiling right now is around 30,000 psi and beyond, with products like Ductal. I think "high strength concrete" is defined as starting at 8,000 or so. Apparently America has the weakest concrete standards, for reasons I don't understand. In Australia, Asia, and Europe, I'm hearing that 5,000 psi is the floor - you'd have to specifically try to produce 3,000 or 4,000 psi concrete in those settings. Just mixing it with normal equipment and processes would get you 5,000+. I'm intrigued by what might be possible with the really good stuff, like seamless concrete roofs, or walls without rebar. For rebar I was thinking about the strength grade, like 60, which seems to be standard, and 75, which is probably rare. 40 is the baseline. This is all ksi yield I think, maybe tensile. Here again, steel gets much stronger than this, mostly in other industries. The impact of 8,000 psi concrete with 75 ksi rebar would be interesting to model. I wonder if strong steel could even eliminate the need for concrete in the "screen grid" systems that use the ICCF blocks, the ones that mix cement and EPS, like Rastra and Bautex.

As an ICF specialist I typically use a 4500 psi mix with 3/8” aggregate. (I typically do everything in 6”). For 8” I do 3/4” aggregate. The idea that smaller aggregate makes a better mix is actually counterintuitive somewhat in that it actually makes it weaker. Thus you should increase the strength of cement content to higher rating to compensate. A varied aggregate mix has better bonding and the varying shapes of small sand, small aggregate, and larger aggregate fill voids better and uses less solid cement particles to fill the voids. The cement is weaker than the aggregates they hold; just as in any composite, the fibers are the strength and the matrix is a binder to hold the fibers in position. So a varied aggregate is best structurally but to allow for a good flow in 6” walls a 3/8” mix is nice. Also, you get less clogging and spurts with the pumps, but it’s usually fine either way. I pour at a 6.5-7” slump, and since I don’t like plasticizers to achieve that (due to the false set it provides and makes anchor bolts difficult to set on large buildings), a 4500 psi mix is likely over watered (because unless you’re strict on your mixture to the batch plant and the truck drivers they will just add water willy nilly) so may settle down and cure to less than the stated value. (At least this is my experience and thinking. I have used plasticizer mud just fine but it costs more for little benefit if any. The concrete is still well over necessary strength in most cases of normal site conditions.). As far as rebar goes, unless it’s ugly soil (expansive and shifty), I usually go with a 32” mat of #4 bar. So every other course horizontally and verticals every 32”. I also alternate horizontals inside and outside of center for above ground and tensile side for below ground. This approach greatly improves the ability of the rebar to do its job by putting the rebar away from the neutral axis of the middle of the wall and acts as a cage for vertical bars to stay retained without tying them. Double rebar on top course typically and I follow a standard rebar schedule for lintels based on FoxBlocks prescriptive charts. They have some of the best prescription charts so I use them independent of brand of block. I install all brands people request, so I deal with several kinds and each has quirks but all work well. The best combination I have used is a blend of them. (StrongHold blocks with Fox HV clips for the first course; those HV clips beat all for fast first courses. However, I haven’t done a Nudura build yet, but think it may be my next favorite block if it works as I believe it will, mostly because it has 8’ forms and collapsing self locking forms.) I have used PolySteel, GreenBlock, FoxBlock, StrongHold, and Logix, as well as LiteForms’ LiteDeck. All good products, so I just recommend whoever is your closest supplier because shipping will bite you and the blocks are pretty similar.

@@JoeDuarteScientist "...like seamless concrete roofs, or walls without rebar." Without rebar? And where would the required tensile strength in this construction approach come form?

@@MrMindlink Good question. I don't remember what I was thinking specifically in that comment, but I assume something like steel fibers, basalt fibers, or some other strong fiber mixed into the concrete. One of the brands of ultra high strength concrete is Ductal, and I think the name is supposed to refer to ductility, and there should be significant tensile strength in their solution.

You have to draw the concrete under the window openings.

@@Challenged1 you do realize SCC flows like pancake batter?

@@rinkevichjm SCC is expensive!!!

@@Challenged1 about 8% for material and after labor is factored in its actually 3% cheaper. the study (done in cheap labor India) ijret.org/volumes/2017v06/i03/IJRET20170603010.pdf

Definitely worth it. I'm not completely sure on the heating side cost because I have 5KW of solar. My average monthly electric bill is $100 per month

No it doesn't. Yes, I am a licensed professional engineer

Typically by code your footer thickness is 1/3 of the width of the footer

@@jameschupp2230 That's the minimum thickness

Yes but why only go 2 feet wide if you’re 16 inches thick, unless the person is using a 2500 psi CONCRETE If you’re on soft soil the width is more important than the thickness that’s my point, and yes I like doing things to ensure better than standard practices.

@@jameschupp2230 For me, the minimum was 21" wide. I was shooting for 24" and ended up around 25-26" wide. For the thickness, I was only required 8" thick and I was shooting for 12" thick. I ended up with 14-16" thick because I was new to using a mini-excavator. Needless to say, a little extra width and depth sure doesn't hurt anything. I'm sure you've heard other engineers say that an engineers personal house will always be built beyond minimum standards for fear of a failure happening while being an engineer.