I'm going to be building a house in the near future, and have been looking at ICF construction for all the exterior walls not just the basement. I think it has some inherent advantages, and with the cost of wood around here (a 1/2" sheet of OSB is $25 a sheet now), I don't know if it will be any more expensive than a conventional concrete basement and stick framing.
So what are the downsides vs upsides?
I hate it. A lot. Its not really waterproof, especially if the guys pouring the concrete havent vibrated the hell out of the wall(which can sometimes result in blowing out the cheesy styrofoam blocks), not really bug proof for the same reasons. Styrofoam is a weak surface and while you can dryvit over it...its still weak. You can side over it but if you are trying to hold down costs by not buying wood.....you arent doing that. One i did years ago was also highly flammable, although i think theyve made strides in that by now.
Upsides......do you really like the throwaway coolers you can buy at grocery stores? I mean, really, really,REALLY like them??? Congrats! You can live in one now!
There is a retired architect in my car club that built his own house with that. He really likes it. His heating and cooling costs are virtually zero.
I've done some studying in building with SIPs. Wood and styrofoam panels and no concrete. The idea of a net zero house or something close it seems cool. Have you looked at using SIPs for the above grade exterior walls?
Dr. Hess said:There is a retired architect in my car club that built his own house with that. He really likes it. His heating and cooling costs are virtually zero.
You can get about the same from tradional framing, r values with standard insulation is probably better these days really
T.J. said:I've done some studying in building with SIPs. Wood and styrofoam panels and no concrete. The idea of a net zero house or something close it seems cool. Have you looked at using SIPs for the above grade exterior walls?
I haven't. At this point I'm still in design phase, So looking at whatever alternatives are out there. While the SIPs appear to be a good idea I don't know that they have any benefit over the ICFs. They also don't have the thermal mass which seems key to the heating/cooling advantages.
ThatsNoUsername said:I hate it. A lot. Its not really waterproof, especially if the guys pouring the concrete havent vibrated the hell out of the wall(which can sometimes result in blowing out the cheesy styrofoam blocks), not really bug proof for the same reasons. Styrofoam is a weak surface and while you can dryvit over it...its still weak. You can side over it but if you are trying to hold down costs by not buying wood.....you arent doing that. One i did years ago was also highly flammable, although i think theyve made strides in that by now.
Upsides......do you really like the throwaway coolers you can buy at grocery stores? I mean, really, really,REALLY like them??? Congrats! You can live in one now!
Can you give me a little background on your experience? Have you had a house made this way or constructed one?
I realize I am going to have to side the house. That is the same either way. It's what is under the skin that I am looking at.
ThatsNoUsername said:Dr. Hess said:There is a retired architect in my car club that built his own house with that. He really likes it. His heating and cooling costs are virtually zero.
You can get about the same from tradional framing, r values with standard insulation is probably better these days really
Is this conjecture or do you have some facts. Based on my reading the thermal bridge values of traditional framing even with spray in foam are much higher. Continuous barrier vs alternating insulation and studs.
In reply to D2W : I used it to build the foundation of my home. If I knew then what I know now I would have used it to build all the walls as well.
I love it! I started out with the foundation to the entrance and right after I started a back problem ( nothing related to working with those light 2 pound foam blocks) had me bedridden as winter approached.
Out of desperation my sister-in-law with no prior construction experience and my 14 year old daughter took on the task with an hour long video and a brief explanation from a heavily drugged me.
They did perfect! Basically in one day ! When it came time to do the pour and vibration I hired two grocery store bag boys about 16-17 years old.
Again perfection!
Waterproof? Yes you have to waterproof any concrete. So you coat it with a tar like substance until you are well out of the ground and then use tyvex or anything similar.
By the time I was halfway done with the foundation I got brave and built in the round! Again it came out perfect and what’s more even with hiring some help and the cost of the forms I saved well over $10,000 for what turned out to be relatively simple and easy work. ( I gave the hard jobs like pouring and vibrating to the bag boys I hired) they made $20 an hour and saved my back!
Now the rest of the story. I bought everything from one source and admitted I had never used the product. Before the pump & cement truck came they sent a supervisor out to check the site. He made a few suggestions that took nearly no time to correct but I suspect helped tremendously. I also did it in three pours rather than all at once like a pro would have. So it cost me a little extra.
I didn’t go with the cheapest. Rather the place with the best support. I may have spent $3-500 more than the cheapest but would do it again in a heartbeat.
Why isn’t it in more common use? Here around the lake about 5% of new construction is ICF and it will be more common. Plus I suspect tradition. Most walls are done with stick framing because it’s fast and cheap plus extremely well known.
Foundations are either poured walls or block. Again pros do it and few want to be the exception.
In reply to D2W :
Ive built a few foundations with it. It was years ago but most people i have talked to that have had it regretted it. It is easy to put together but its also pretty easy to fail horribly at. Concrete weighs 2 tons a cubic yard, and you are holding it back with styrofoam, things happen. Ive seen the plastic reinforment shatter under concrete load too, luckily for me i didnt trust it and braced it so it was only a small disaster.
Looking online i see that ICF has about 20-22 for an r rating. Thats about the same as what is code for a 2x6 wall. While i know what you are saying about thermal bridging i can only tell you this. I built a simple house in north idaho with 2x6 walls r22 insulation. The house has never dropped below 55 degrees, even without any source of heat for months on end and in subzero temps. I did do a slab on grade with post holes dug 2 feet into earth to take advantage of the earth temp. In summer its never got above 78 without ac even when it was 104 outside. It uses wood heat and during winter months i burn a cord and a half of firewood. if you arent careful the fire will heat the house to over 90 degrees. Its nit a huge house 1024sq ft, but to me that is impressive.
I also highly doubt that concrete is cheaper than framing, i have a construction company and although i know it fvaries wildly by region i cant imagine concrete ever being cheaper.
In reply to D2W :
The R value of a 2x4 is about 2 so even with R13 walls you have a 1&1/2 wide area of R2
top and bottom. Both sides, every 16 inches. If you use fiberglass you have air movement inside the wall cavity. Hot air rises cold air settles. Round and round in the cavity scrubbing heat out
Cellulose doesn’t have the air movement issues but has issues of its own. Spray foam is much better but costs increase significantly. With all three methods you have that low R value at the stud.
If you’d like numbers,
i owned the house before I tore it down for about 20 years. It was approximately 2300 sq ft. Well insulated fiberglass walls and cellulose ceiling. Good vapor protection without any flaws that Zi found in demolition. With something like 30 windows, newish Andersen double pane.
Dec& Jan heat bills were always $500+ mo.
Using the same furnace with higher gas prices. I am now heating 5500 sq ft with 105 Andersen windows.
Dec&Jan heat bills are $300. Month same furnace tuned up every fall! That’s an average over a 10 year period!
I think Frenchy and ThatsNoUserName should settle this in a cage wrestling match in Jello. 
In reply to frenchyd :
That is good to know. I'm not really looking to DIY, I just thought with rising construction costs it might be a good alternative. I have a couple of friends who are concrete guys who I would have do the work. One of them is where I got the idea. We also have a local company who makes the forms who I can buy direct from. I only know two people who have used it for basements, and they seem to be happy with it.
The real world thermal performance of ALL wall systems has nothing to do with R values, and everything to do with workmanship, attention to detail, and humidity transfer.
Before I used ICFs, I would become intimately familiar with the issues related to termite infestation. A system that requires putting styrofoam in contact with the ground is an invitation for an infestation.
SVreX said:I think Frenchy and ThatsNoUserName should settle this in a cage wrestling match in Jello.
But what is the R value of jello?
SVreX said:The real world thermal performance of ALL wall systems has nothing to do with R values, and everything to do with workmanship, attention to detail, and humidity transfer.
Before I used ICFs, I would become intimately familiar with the issues related to termite infestation. A system that requires putting styrofoam in contact with the ground is an invitation for an infestation.
That is something to be aware of, although in our climate termites are not really much of a problem.
SVreX said:I think Frenchy and ThatsNoUserName should settle this in a cage wrestling match in Jello.
Im not that interested in it lol
"Before I used ICFs, I would become intimately familiar with the issues related to termite infestation. A system that requires putting styrofoam in contact with the ground is an invitation for an infestation."
This is true and a downside definitely
D2W said:SVreX said:The real world thermal performance of ALL wall systems has nothing to do with R values, and everything to do with workmanship, attention to detail, and humidity transfer.
Before I used ICFs, I would become intimately familiar with the issues related to termite infestation. A system that requires putting styrofoam in contact with the ground is an invitation for an infestation.
That is something to be aware of, although in our climate termites are not really much of a problem.
You and i are from the same area from your profile, agreed there.
I've worked on two of them (ironically at the same time) and it was a huge pain in the ass. Everything we did was drilling into concrete. None of the window openings were spec or remotely close to level. One wall in a stairwell was an inch and a half out of plumb. Hanging drywall on that was interesting. I'm glad it wasn't me.
That said.
That was E36 M3ty contractor, and shoddy workmanship. Had they taken their time and plumbed everything, those problems wouldn't have been too bad.
But everything that you would normally run in a wall, had to be chiseled out of concrete. So everywhere you looked. Plumbers, electricians, security guys, whatever are chiseling out concrete to run conduit.
I'm sure the efficiency would pay off in the long run, but it is a LOT of headache.
I'm glad I don't build stuff anymore.
My current understanding is that all the electrical and plumbing are ran in the foam. Unless you are going outside why would they be chiseling concrete?
In reply to D2W :
Because there is a gap between what the designers conceive and what is actually done in the field.
Very few tradesmen know how to work with ICFs, and very few ICF engineers know how to work with tradesmen.
ThatsNoUsername said:In reply to D2W :
Ive built a few foundations with it. It was years ago but most people i have talked to that have had it regretted it. It is easy to put together but its also pretty easy to fail horribly at. Concrete weighs 2 tons a cubic yard, and you are holding it back with styrofoam, things happen. Ive seen the plastic reinforment shatter under concrete load too, luckily for me i didnt trust it and braced it so it was only a small disaster.
Looking online i see that ICF has about 20-22 for an r rating. Thats about the same as what is code for a 2x6 wall. While i know what you are saying about thermal bridging i can only tell you this. I built a simple house in north idaho with 2x6 walls r22 insulation. The house has never dropped below 55 degrees, even without any source of heat for months on end and in subzero temps. I did do a slab on grade with post holes dug 2 feet into earth to take advantage of the earth temp. In summer its never got above 78 without ac even when it was 104 outside. It uses wood heat and during winter months i burn a cord and a half of firewood. if you arent careful the fire will heat the house to over 90 degrees. Its nit a huge house 1024sq ft, but to me that is impressive.
I also highly doubt that concrete is cheaper than framing, i have a construction company and although i know it fvaries wildly by region i cant imagine concrete ever being cheaper.
You are most likely right, it’s not Cheaper. Although it was about $10,000 cheaper than the best quote of either poured concrete or block walls. ( mainly because my total labor bill was under $500 and all I paid for was materials. It is better at stopping bullets insert smiley face here. and also keeping in heat.
The advantage is more than the R 22 value. It’s virtually no thermal bridging which stick built cannot claim. Plus the gain of thermal mass which fiberglass doesn’t have.
SVreX said:In reply to D2W :
Because there is a gap between what the designers conceive and what is actually done in the field.
Very few tradesmen know how to work with ICFs, and very few ICF engineers know how to work with tradesmen.
You are right. ICF’s are not a standard item. The 4 in my neighborhood are really great looking houses and very much not done on the cheap.
The owners easily could have afforded a regular house but these people did their research. They spent millions and wanted the best. They choose ICF’s.
I haven’t designed or built one but I’ve read extensively on the topic. My #1 concern (assuming there is a basement) is waterproofing the ICF below grade, extending the same waterproofing above grade and making a water tight transition to the above grade wall cladding. #2 concern is keeping walls plumb and getting rough openings correct. It is a LOT harder to cut a hole through an ICF wall than a stick framed wall.
Isolated thermal mass is amazing for maintaining a steady temperature.
Related: https://youtu.be/MRipzKkeQik
In reply to OHSCrifle :
Waterproofing is really straight forward. I used the same tar like substance used on concrete walls. Kinda messy so wear your worst clothes you intend to throw away, and cover your hair!!! ( please don’t ask ) Just like any foundation get well above the soil level!
Protection above grade is Tyvex and I let it run a little long and then “glued” it down with a brush width of the same tar like substance.
I did the first section in 2001 and that corner which had been a real trouble spot in the past because of run off from my neighbors roof and driveway etc comes flooding in every time we get a heavy rain.
Not a spec of moisture!! Gets inside. The Sheetrock would have gotten moldy if any came in. It’s dry as a bone. In fact my whole basement is nice and dry.
Keeping things plumb is the same as anything.They make it simple with the scaffolding/bracing they rent. There are a few techniques to check. that’s why you use their scaffolding and have someone familiar with the process check your work before the pour.
I really fought them because I own my own scaffolding and couldn’t understand why I should pay to borrow theirs. I’m glad they insisted. Now I understand.
Here it helps if you admit you don’t know. The help was free( or included in the purchase)
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