Awesome video awesome tips!! I’m gonna add some that I’ve learned -A skill saw will give you the quickest easier straightest cut - a 2’ 1x4 is nice for smacking down icf your hand will hurt, just hit both sides at the same time and it should be fine. - DONT forget your shades - your bracing needs to have slots and screws with washers that are loose enough to slide, but tight enough to keep the wall straight. If the icf isn’t allowed to settle it WILL separate. We use 1x4 screwed in an L stud with slots, spaced every 5 feet. - an 8 foot wall will settle about 1/2 inch - always measure a 1/4-1/2 inch small cause it can easily grow which is a nuisance for framing - outside corners are your weakest spot - we personally have 3 guys on pour days, one is pouring 2 are watching for blowouts/weak spots. - Manuel rebar cutter bender is what we use. Works for us. Hope this helps someone.
we're just starting the process of building our icf home. I just wanted to say your content has been super helpful and informative across the board! thank you so much!
Mr G. After working 25 years in many different areas of construction and finishing, and building 3 of my own personal homes, I chose to do an icf for most of the beneficial reasons. Right off the bat, even though I have drawn all my homes, I also find the block thickness issue nerve racking. Thank you for documenting your thoughts and experiences.
Hit that like!! Been looking at ICF for 15 years finally at build stage and looking for land. Would love to hear from you for more advice and what I'll expect down the road
I like the video, one question on ICF, is there a fairly simple rebar reinforcement spacing you used ? No one can come up with that.I am using 6 inch Buildblock. One common thread seems to be 1 # 4 bar every 16 inches horizontally, which works well with 16 inch block. I have not heard any good direction on the vertical rebar, other than 2 vertical rows each side of doors and windows, as well as lentils are fairly straight forward. Sheer wall is another issue. I cannot seem to find any engineers for ICF, which I have been Working with engineers for concrete footers for 25 years. Any info would help.
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.
Hi Garrett, We are just starting our ICF house also using form-a-drain. I appreciate the videos and your experience. Thanks for sharing. We aren't that far away. We are building in Mound City, KS over on the MO line just a few miles North of 54.
Thank you so much for your insightful videos! I live in Salina and hope to build an ICF home in the next three years. I hope I can reach out to you for advice and counseling.
Building an ICF house soon...had to end up stick framing 2 walls in the design due to the amount of windows I'm installing but I'm super pumped for the final result!
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.
Garrett, I was watching this video and I noticed when you had the shot of the concrete pour of the floor you had your vapor barrier plastic underneath your 1 inch foam insulation. But you have another video that says to do it with the foam on the bottom and the plastic on top. Can you clarify that please and thank you
Great video..thanks for taking the time to share! Planning on building our first ICF home ever (1st any home!) This video will help us out a lot! Have a great day sir!🎉
Hi I’m interested in building in icf with my wife, doing most ourselves. Can you fill each layer of blocks with concrete individually then put the next layer of blocks on when it has gone hard?
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.
That was interesting. About #3 - the second row. Why not build first and second row at the same time? That would keep everything tight right from the start
@@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.
@@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.
Did you ever look into the Zont/Zuckle system for bracing? A lot more affordable (maybe not so much anymore with high wood prices, but you can reuse the wood later) and not nearly so heavy or difficult to deal with. They seem like a great bracing system.
Nice work. Did your need an engineer? I'm interested in the structural details. Do you know how strong your concrete and rebar were? The specs I've seen from Quadblock and Nudura said something like 2,500 to 3,000 psi concrete, with no details about the rebar grade. That's pretty weak concrete at this point, and I wonder if going with a much stronger concrete, maybe with high grade rebar, would enable the concrete section to be thinner, like 4 inches instead of 6, and then exploit that savings for more insulation. The insulation on most blocks seems too thin, especially if they're using vanilla EPS Type II.
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.
Hey Garrett I’m a recent subscriber and fellow engineer. I really appreciate your videos that I have seen so far. I’m really into relistate and can’t express how valuable it is to have some of these ideas and resources consolidated into one place, so thank you for that. Do you take suggestions on content for future videos cause I have some questions I’d like answers to that you potentially have insight 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.
Great tips! I disagree with the hammer vs hand tip. The best is one of the orange sand filled mallet from harbor freight. (Buy two) You only strike the nubs with ties, they are made to hit. I also didn't even use a top plate. I am pouring my gables and embedded a tie strap into the wet concrete for every truss heel. I'm setting the trusses right on the concrete.
Hello Garret, we're just in the process of designing our very own ICF home and had a question for you: in your opinion does it make sense to design the floor plan dimensions so that they allow for minimal cutting of the blocks, potentially reducing the quantity of blocks required? Or is this such a small portion of the project that we're better off not worrying about block sizes/cutting during the design process? Thanks and great work on the video, they've been really helpful!
Garrett, thanks for your videos on ICF. I plan to build an ICF home in about 2 years time and your advice and perspective has been invaluable. I had a question. Although my contactor does have some experience building ICF homes, I don't think he would consider himself an ICF master builder. That said, I was wondering if you thought it would be a good idea to hire a professional advisor for 1-2 days right before pour to absolutely make sure that the ICF blocks have been installed and braced in a proper manner? Is it worth it to hire an ICF professional to double check and give a 2nd pair of eyes to the set up prior to pour or just save the money and go with my local ICF builder who has experience but isn't an absolute expert? New subscriber!
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.
Hi. Great videos.. I'm looking to build an ICF home in Chapman KS. Any issues after the build you are willing to share? Moisture problems, heating and cooling, out of square problems?
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.
Would a 4x2 frame brace inside each door/window opening be a good idea to stop the sides and top bowing in? Could you use the primer when you first lay the books. I mean is the primer protective against UV? Would pre stressed concrete lintels be a useful addition at window and door openings with wood shuttering beneath? They are probably overkill, but wont dip under the concrete pour and are extremely strong.
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.
In terms of tapping in the ICF blocks... better advice, have a sacrificial block or two and use a rubber mallet. Instead of directly hitting the blocks that you place, use a sacrificial one that will get damaged and tap it.
Wow on your footers!! My engineer wrote us up for 1500psi soil at 25”x8” for the house and 16”x8” for the garage. The basement is 6”x10’8” walls and the house is 4”x10’5” walls. The garage is 6”x6’8” with 12’ stud walls. But I’m closer to your numbers. We bought 2x10’s instead of 2x8’s for the footer foams so I’d say on average we’re about 12” thick as the excavation wasn’t perfect and most were off the ground. The garage I actually kept it the same so everything is 25”x9.5-16” depending. I used the sill seal on the garage walls with caulking but for the house used 3 rows of spray foam then placed the sills wet. Should do the trick.
@@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
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
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.
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.
Want to build your house? Check out this spreadsheet - it helps estimate cost/ schedule, and provides a step-by-step checklist. Great for General Contractors or first-time home builders. Purchase here etsy.me/2X7aFiV Tutorial on UA-cam: ua-cam.com/video/Z1oKUtBGwXI/v-deo.html
this is ridiculously good advice. This man has installed ICF unlike alot of videos out there.
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
Thanks Garrett. Second time I watched this video… refresher.
I hope it helps
Awesome video awesome tips!! I’m gonna add some that I’ve learned
-A skill saw will give you the quickest easier straightest cut
- a 2’ 1x4 is nice for smacking down icf your hand will hurt, just hit both sides at the same time and it should be fine.
- DONT forget your shades
- your bracing needs to have slots and screws with washers that are loose enough to slide, but tight enough to keep the wall straight. If the icf isn’t allowed to settle it WILL separate. We use 1x4 screwed in an L stud with slots, spaced every 5 feet.
- an 8 foot wall will settle about 1/2 inch
- always measure a 1/4-1/2 inch small cause it can easily grow which is a nuisance for framing
- outside corners are your weakest spot
- we personally have 3 guys on pour days, one is pouring 2 are watching for blowouts/weak spots.
- Manuel rebar cutter bender is what we use. Works for us.
Hope this helps someone.
Excellent tips!!!
I love that your 'extra help' clip included a baby in a stroller! 🤣That is one fussy foreman. PS thanks for this video 👍
He loved being on site. It always amazed me that he could sleep with all the noise around.
we're just starting the process of building our icf home. I just wanted to say your content has been super helpful and informative across the board! thank you so much!
I'm so happy to help!!!
great advise,im sticking with my logs,,,the biggest ticket item is my stihl chainsaw,,
Mr G. After working 25 years in many different areas of construction and finishing, and building 3 of my own personal homes, I chose to do an icf for most of the beneficial reasons. Right off the bat, even though I have drawn all my homes, I also find the block thickness issue nerve racking. Thank you for documenting your thoughts and experiences.
Thanks for all that knowledge
Thank you for a great information!
You're welcome
Thank you for all your ICF expertise Garrett. I really appreciated the bit about over sizing the rough openings and your actual footing dimensions.
Glad to help
What do you think about using Traditional forms and form ties with icf?
Hit that like!! Been looking at ICF for 15 years finally at build stage and looking for land. Would love to hear from you for more advice and what I'll expect down the road
I've made a bunch of ICF videos which might answer most of your questions. Check out my channel page to find those.
I like the video, one question on ICF, is there a fairly simple rebar reinforcement spacing you used ?
No one can come up with that.I am using 6 inch Buildblock. One common thread seems to be 1 # 4 bar every 16 inches horizontally, which works well with 16 inch block. I have not heard any good direction on the vertical rebar, other than 2 vertical rows each side of doors and windows, as well as lentils are fairly straight forward. Sheer wall is another issue. I cannot seem to find any engineers for ICF, which I have been
Working with engineers for concrete footers for 25 years.
Any info would help.
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.
Hi Garrett, We are just starting our ICF house also using form-a-drain. I appreciate the videos and your experience. Thanks for sharing. We aren't that far away. We are building in Mound City, KS over on the MO line just a few miles North of 54.
Good deal. I wish you luck with your build!!!
Thank you so much for your insightful videos! I live in Salina and hope to build an ICF home in the next three years. I hope I can reach out to you for advice and counseling.
Thank you for providing such detailed information about your ICF build! I apologize if you have already covered this in a video but
Building an ICF house soon...had to end up stick framing 2 walls in the design due to the amount of windows I'm installing but I'm super pumped for the final result!
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.
Loved the information! Kudos
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
USEFUL!!!!!!! Thanks. I’m thinking about an icf basement
Glad it was helpful!
Garrett, I was watching this video and I noticed when you had the shot of the concrete pour of the floor you had your vapor barrier plastic underneath your 1 inch foam insulation. But you have another video that says to do it with the foam on the bottom and the plastic on top. Can you clarify that please and thank you
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.
Buy as much gravel as deep as possible. Preferably almost within two feet of surface.
Thanks, I hope to build my own someday.
You can do it, and it's worth it!
Great video..thanks for taking the time to share! Planning on building our first ICF home ever (1st any home!) This video will help us out a lot! Have a great day sir!🎉
I'm glad this will help you out. Good luck with your build!!!
Hi I’m interested in building in icf with my wife, doing most ourselves. Can you fill each layer of blocks with concrete individually then put the next layer of blocks on when it has gone hard?
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.
That was interesting. About #3 - the second row. Why not build first and second row at the same time? That would keep everything tight right from the start
I put horizontal rebar on every row, which means each row gets built separately.
Tip #6 can't be over emphasized. Sunny or cloudy day makes no difference, sunglasses are a MUST!
I have used the form a drain, any thoughts on fastfoot/monopour?
I don't have any experience with them
Great channel Garret. Question for you: did you use some sort of mechanical ventilation system; hrv, erv, etc?
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.
The rebar bender in your description, did you use that same tool for bending your stirrups, too?
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
Did you ever look into the Zont/Zuckle system for bracing? A lot more affordable (maybe not so much anymore with high wood prices, but you can reuse the wood later) and not nearly so heavy or difficult to deal with. They seem like a great bracing system.
I think they would be great with engineered lumber. Stock lumber just doesn't stay straight long enough
Nice work. Did your need an engineer? I'm interested in the structural details. Do you know how strong your concrete and rebar were?
The specs I've seen from Quadblock and Nudura said something like 2,500 to 3,000 psi concrete, with no details about the rebar grade. That's pretty weak concrete at this point, and I wonder if going with a much stronger concrete, maybe with high grade rebar, would enable the concrete section to be thinner, like 4 inches instead of 6, and then exploit that savings for more insulation. The insulation on most blocks seems too thin, especially if they're using vanilla EPS Type II.
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.
Hey Garrett I’m a recent subscriber and fellow engineer. I really appreciate your videos that I have seen so far. I’m really into relistate and can’t express how valuable it is to have some of these ideas and resources consolidated into one place, so thank you for that. Do you take suggestions on content for future videos cause I have some questions I’d like answers to that you potentially have insight for?
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.
Great tips! I disagree with the hammer vs hand tip. The best is one of the orange sand filled mallet from harbor freight. (Buy two) You only strike the nubs with ties, they are made to hit. I also didn't even use a top plate. I am pouring my gables and embedded a tie strap into the wet concrete for every truss heel. I'm setting the trusses right on the concrete.
Hello Garret, we're just in the process of designing our very own ICF home and had a question for you: in your opinion does it make sense to design the floor plan dimensions so that they allow for minimal cutting of the blocks, potentially reducing the quantity of blocks required? Or is this such a small portion of the project that we're better off not worrying about block sizes/cutting during the design process? Thanks and great work on the video, they've been really helpful!
The more effort you put into the design, the faster and cheaper the house will be. Yes, it's worth your while.
Garrett, thanks for your videos on ICF. I plan to build an ICF home in about 2 years time and your advice and perspective has been invaluable. I had a question. Although my contactor does have some experience building ICF homes, I don't think he would consider himself an ICF master builder. That said, I was wondering if you thought it would be a good idea to hire a professional advisor for 1-2 days right before pour to absolutely make sure that the ICF blocks have been installed and braced in a proper manner? Is it worth it to hire an ICF professional to double check and give a 2nd pair of eyes to the set up prior to pour or just save the money and go with my local ICF builder who has experience but isn't an absolute expert? New subscriber!
I think a 2nd pair of eyes is never a bad thing if it makes you feel more comfortable.
Wow, you where able to put you footing on expansive soil? I figured you would have to have deep peers installed to prevent from heaving?
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.
Where did you buy the dimpled underlayment?
Menards
@@Challenged1 thanks
Hi. Great videos.. I'm looking to build an ICF home in Chapman KS. Any issues after the build you are willing to share? Moisture problems, heating and cooling, out of square problems?
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.
Would a 4x2 frame brace inside each door/window opening be a good idea to stop the sides and top bowing in?
Could you use the primer when you first lay the books. I mean is the primer protective against UV?
Would pre stressed concrete lintels be a useful addition at window and door openings with wood shuttering beneath? They are probably overkill, but wont dip under the concrete pour and are extremely strong.
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.
In terms of tapping in the ICF blocks... better advice, have a sacrificial block or two and use a rubber mallet. Instead of directly hitting the blocks that you place, use a sacrificial one that will get damaged and tap it.
Good idea
I hit "Like" so I did my part for structural integrity :-}
I sure appreciate it!!!
Wow on your footers!!
My engineer wrote us up for 1500psi soil at 25”x8” for the house and 16”x8” for the garage. The basement is 6”x10’8” walls and the house is 4”x10’5” walls. The garage is 6”x6’8” with 12’ stud walls.
But I’m closer to your numbers. We bought 2x10’s instead of 2x8’s for the footer foams so I’d say on average we’re about 12” thick as the excavation wasn’t perfect and most were off the ground. The garage I actually kept it the same so everything is 25”x9.5-16” depending.
I used the sill seal on the garage walls with caulking but for the house used 3 rows of spray foam then placed the sills wet. Should do the trick.
Excellent, thanks for sharing.
Why would you need to vibrate if you specify SCC like you should?
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
@@Challenged1not as expensive as vibrators and labor and fixing voids because you missed a spot.
are superplasticizers viable with ICF? The extra cost could be offset by easy of flow and less labour vibrating
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
Hi Garrett congrats on an awesome ICF project..did you ever consider doing the roof also with ICF either sloped or flat ?
My house is so big, the spans are too long.
Great videos Garrett! Did you consider using Helix micro rebar?
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.
Regarding help during your pour, I suggest you modify the budget for some top shelf steaks. Bribery gets you everywhere.
Thanks for the vid and not sure what kind of idiot would give this a thumbs down, keep them coming. Loved your Geothermal video
Thank you for the kind words
Is icf house worth it the money what is your heating cost
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
If your footers were 16 inches thick, then that would mean by code you would have a 4 foot wide footer
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.
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