ICF homes

Joined
Sep 28, 2018
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2,242
Location
VA
I see several folks around me building with that stuff. I wonder about how you finish it with siding and interior walls. I also wonder about its longevity.

All the past failures like LP siding, polybutylene plumbing, vinyl siding, stucco that rotted the sheathing and framing, mold issues due to houses not breathing, ect…

Seams just about any time they come up with a new material or new way to use plastic it comes with a 20 year learning curve.

ICF blocks have strips in them that can be screwed directly into OR you could using furing strips of you wanted some additional wall cavity space

I've never use PB plumbing or stucco, but LP and Vinyl siding have their place. My house has had vinyl siding for 26 years. Its still there. Doesn't look fabulouse and it'll go right into the land fill instead of being able to be painted or crushed into a re-useable product.

When I redo my siding and roof i'm going with hardi siding and metal roofing. Both are bomb proof 100 year products
 

hunterjmj

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Feb 3, 2019
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1,399
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Montana
We're pouring an icf crawl space foundation this spring. Just waiting on the weather. Our old house had tge same foundation with LP smartside and the stuff still looked new when we moved. I wouldn't put smartside if I lived in western Washington but works great here.
 

f16jack

WKR
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Jun 27, 2020
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324
Location
Utah
I see several folks around me building with that stuff. I wonder about how you finish it with siding and interior walls. I also wonder about its longevity.

All the past failures like LP siding, polybutylene plumbing, vinyl siding, stucco that rotted the sheathing and framing, mold issues due to houses not breathing, ect…

Seams just about any time they come up with a new material or new way to use plastic it comes with a 20 year learning curve.
You mentioned a house being able to "breathe." My SIP ICF home does not breathe. It is pretty much airtight, as it should be. That's why in new construction "non-drafty" houses you install an air exchanger to handle humidity and fresh air.
 

benh

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Jul 13, 2019
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3
I'm a structural engineer and a contractor. My 1st experience with ICF's was in the late 90's and I couldn't get a sub contractor to do a foundation on my family's cabin, so I looked at renting forms to do it myself and it was about the same cost of ICFs so I just used them. My intent was just to get a foundation, it wasn't till afterwards that I realized some of the other benefits, such a far superior energy efficiency, 0 air infiltration, sound, etc. On properties I intend to keep, ICF's are the way to go IMO. For a spec home or short ownership period, I wouldn't use them because they do cost somewhat more, but most buyers, don't know or care about anything that you don't see, so just as well use the cheapest thing that will last a couple years.

As far as skilled workers, any carpenters should be proficient at building with these with a pretty short learning curve and a some videos. I can see a one-trick pony framing crew struggle with them.

Here are a few pics of a beach home we're building for a customer with ICFs from the footings, to the 2ndfloor.
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IMG_5929.jpegfront bsmt.jpeg
 

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Joined
Apr 13, 2019
Messages
549
Our current place has a big ICF basement and our family has built 3 houses using ICF basements, one of which was 1 1/2 stories of ICF with a big vaulted roof system resting on the ICF’s. The three built in the family were done by amateurs and all held up well with no issues. The bracing systems and current ICF systems themselves have come a long way. The wall sizing has to be matched to your structural requirements, soil types, and depth obviously. Our next place will have an ICF foundation for sure.
The house that was all ICF walls and a roof system suffered a fire and was a total loss. It was interesting to see the walls after the foam was burned off, pretty good size house and the only flaw in the concrete was a small void around a door frame.
Pouring the window and door frames can be made easier by building it in such way as to leave to bottom sill out or at least a portion of it to pour through or verify you got concrete to it. Watched a guy who'd been doing it for 20 years struggle in that area and couldn't believe he hadn't made that part easier for himself. Once its poured install the plates.
They get used alot around here, since the new bracing systems guys seem to be able to get them trued up, but in the beginning I heard alot of carpenters complain about walls out of plumb and square. They aren't water proof, you have to take steps to waterproof them like everything else and make sure your drainage and gutters are adequate.
The 2 structural failures I'm aware of locally involved backing a concrete truck to close to one and a really big one with a long, deep, unsupported back wall on a walk out. That one probably needed some kind of additional bracing due to the length.
 
Joined
Apr 21, 2015
Messages
998
You mentioned a house being able to "breathe." My SIP ICF home does not breathe. It is pretty much airtight, as it should be. That's why in new construction "non-drafty" houses you install an air exchanger to handle humidity and fresh air.
Yes, I'm familiar with the new methods of installing a low flow fan setup, or fans on timers with window or other intake vents to provide the air exchange in new construction sealed up houses. I believe these days the standard is the low flow constant on fan setup rather than the fans on timers. Again with that 20 some odd year learning curve.

I'm not saying I don't like the foam and plastic concrete forms or that I believe they are an issue, just that I wonder about the longevity and future issues they may present.
 
OP
Mojave

Mojave

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One of the key components of a modern house build in the North or Rockies is putting a hydro-thermal flooring system in.

We had a approx 55 gallon drum in Germany that we would fill up twice a year. A pump ran heated water through lines in the floor that were in covered with concrete when the floor was poured.

Floor was always warm to the touch in the winter. Our youngest would zonk out on one of the Persian carpets on the tile. I would imagine if you had pets they would do the same.

Germans open windows even in the middle of winter to circulate cold fresh air. Stoßlüfte they call it shock ventilation. They will do this several times a day. Bathroom windows are generally left open before ,during and after showers.

We had our laundry room open when the washer and dryer was running.

Our house was crazy tight with zero air exchanges. But the Stoßlüfte helped to insure we didn't have mold.

Mold is a problem if you don't figure out a way to have somekind of air exchagne sysystem.
 

Preston

Lil-Rokslider
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May 12, 2020
Messages
192
I’ve used Logix and Nudura blocks for three frost walls and recently built my own house out of Logix icf up to the 10’ wall height. I will never go back to wood framing for exterior walls. I used Raycor sip panels for the roof and have been satisfied with my first winter in this house in northern MT. Have only used wood heat. I purchased a bracing/scaffolding system which works great (Plumwall). I had a contractor/distributor really provide some great ideas on window and door bucks. The only issue we had was cutting holes in the window seals and putting additional concrete during the pour or you will end up with voids.9CA301F3-A675-43B1-AD6D-C29B130A8E54.jpeg4C5CCAA9-1DA1-4BF6-82B6-0205BEAA40D8.jpeg
 
OP
Mojave

Mojave

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I’ve used Logix and Nudura blocks for three frost walls and recently built my own house out of Logix icf up to the 10’ wall height. I will never go back to wood framing for exterior walls. I used Raycor sip panels for the roof and have been satisfied with my first winter in this house in northern MT. Have only used wood heat. I purchased a bracing/scaffolding system which works great (Plumwall). I had a contractor/distributor really provide some great ideas on window and door bucks. The only issue we had was cutting holes in the window seals and putting additional concrete during the pour or you will end up with voids.View attachment 534340View attachment 534341
Thank you for dumbing it down enough for us retards. Man that great room is GREAT!
 

Boog304

FNG
Joined
Mar 2, 2019
Messages
36
Location
WV
Current home basement I used icf and did it all myself, with no issues. I am no contractor and plan on starting a house this summer and will do the basement in icf, again by myself.

Current basement it about 1800 sf and is daylighted on two sides with two 9’ garage doors in one end. The slab has hydronic heating and heats the space with very little effort. But I swear you could heat the basement with a candle, it is so well insulated and no air infiltration.

As others have said there are some things to consider and termites and waterfroofinf are at the top but the new building methods take care of that.

Best of luck
 

KurtR

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Sep 11, 2015
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South Dakota
Yes, I'm familiar with the new methods of installing a low flow fan setup, or fans on timers with window or other intake vents to provide the air exchange in new construction sealed up houses. I believe these days the standard is the low flow constant on fan setup rather than the fans on timers. Again with that 20 some odd year learning curve.

I'm not saying I don't like the foam and plastic concrete forms or that I believe they are an issue, just that I wonder about the longevity and future issues they may present.
They have been in use for way more than 20 years . The first icf came out in 1968.
 
Joined
Apr 13, 2019
Messages
549
For the guys that had voids.... Did you use a vibrator on the wall?
I think they really frown upon using a traditional vibrator on them. We used cordless sawzalls without a blade run along the walls.
Like I said, that one house was 1 1/2 stories and the only void was about the size of your hand where a door frame and window frame were within a foot of each other.
I'm not up on it, but I'm sure there's a recommended concoction of plasticizers out there to assist/optimize the pour.
 
Joined
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Upstate NY
I think they really frown upon using a traditional vibrator on them. We used cordless sawzalls without a blade run along the walls.
Like I said, that one house was 1 1/2 stories and the only void was about the size of your hand where a door frame and window frame were within a foot of each other.
I'm not up on it, but I'm sure there's a recommended concoction of plasticizers out there to assist/optimize the pour.
Same here. We bounced a sawzall without a blade against the forms.
 

CB4

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Joined
Oct 10, 2018
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Location
Iowa
Wanting to buy some property and build an ICF house. I would do the entire exterior structure out of it. Like mentioned the long term benefits greatly outweigh the initial cost. I have seen two built in the last 3 years. Neither had to run A/C in the dead heat of summer while under construction. Pair it with a nice fireplace and the energy savings would be astounding. The cost of materials has gone down but for about a year ICF was actually cheaper to build.
 

Preston

Lil-Rokslider
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May 12, 2020
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For the guys that had voids.... Did you use a vibrator on the wall?
I’ve had voids, and it was mostly underneath windows. I would use a pencil vibrator on every lift. Pour each pass at 2-4 foot and let it set up for 15-20 minutes before you do your next pass. A sawzall along the plastic gussets also work for the bottom pour on top of the footing
 

KurtR

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Sep 11, 2015
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South Dakota
I’ve had voids, and it was mostly underneath windows. I would use a pencil vibrator on every lift. Pour each pass at 2-4 foot and let it set up for 15-20 minutes before you do your next pass. A sawzall along the plastic gussets also work for the bottom pour on top of the footing
From everything I know about concrete in the last 25 years a cold joint in walls is the last thing you want. Try and tell the pump truck guy to just sit there and wait you will have a problem as the mud sets up in his truck. There are actually specs on big commercial jobs you can’t have that much time in between trucks just so it doesn’t start setting up in the walls.
 

Preston

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From everything I know about concrete in the last 25 years a cold joint in walls is the last thing you want. Try and tell the pump truck guy to just sit there and wait you will have a problem as the mud sets up in his truck. There are actually specs on big commercial jobs you can’t have that much time in between trucks just so it doesn’t start setting up in the walls.
We don’t stop the pump truck, but just pour in lifts at several feet each pass. Just walk around the walls pouring concrete and guy right behind vibrating. Do not pour all the way to the top of the wall, unless you want a blow out
 
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