Anyone with ICF building experience?

[dalola]

I'm several years away (5'ish?) from a retirement cabin project, been looking at various building methods. In a perfect world, I'd just do a small (~1K f2, one story w/ walk-out basement on a hillside) log cabin, but then I start thinking about maintenance, battling the critters, etc.. Not sure I want to go down that road again, as I currently have an all cedar home. Love the wood, hate the maintenance and constant battle with pests. And this will be in the middle of the woods in BFE south east Ohio!

Also like timber framing/SIP, but not convinced SIP's are the answer either.

Started researching ICF's, specifically the Nexcem/Faswall style wood-mix block, and Bautex EPS block. They both have a lot of appeal to me, for all the well known reasons.

Does anyone have any ICF experience, especially with these brands? Don't think I'm interested in the traditional plastic type forms, but maybe I should be? The blocks really make a lot of sense to me.

Anyway, just looking for experiences anyone has with ICF's in general, good or bad. Who knows, may be something way better in 5 years!

Feel free to add in any other alternative construction methods that deserve some research.

 

[mikester]

I used the blue-max ICF system and have been happy with it.

If I build again I would go to the roof with ICF and use SIP for the roof. Think Thermos-Bottle.

Blue-max uses plastic studs 8 inches on center and drywall is a breeze to install. The negative is that if you drywall directly to it you have to cut channels for the electrical so pre-planning is required and if you hire electricians you will have to put up with their whining. If I build again I would install EMT or conduit traces to make later retrofits easier as you can't snake wires through the finished walls on ICF.

Hire a good experienced contractor with the right equipment/supports to install. Get the wrong guy and you will have wonky walls and possible blowouts during the pour. I wouldnt attempt doing a one man install, just too much going on during the pour.

ICF Pros: very good insulation and sound deadening, tornado proof, thermal mass means cooler in summer and warmer in winter, stable wall system (ie. no wood shrinkage), add triple glazing and you end up with a very quiet house, easy to have high ceilings without large added costs, air-tight and energy efficient

Cons: more expensive up front, need skilled labor to install, electrical and plumbing stacks need pre-planning, listening to contractors whining because the cant blow holes wherever they feel like it. You will need an ERV/HRV because of the air-thight construction

I've heard a lot of horror stories about bad installs by inexperienced contractors and bugs moving in ie. ant colonies moving into the foam. I've been in it for 20 years and, knock on wood, have had no such issues.

Here's a good quote for you to consider - 80 percent of the building's cost over its lifetime is in the day to day operation for things like heating and cooling - only 20 percent is the actual construction cost.

Spend your money upfront on insulation and good planning and you will save in the long run with low living costs and comfort.

Google Passivhaus and passive solar design.

 

[Diggin It]

You gonna tell us what 'ICF' is?

 

[3Ts]

You will need to be there when they set the forms. My neighbor did an ICF and they set the forms and poured while he was on vacation. They mis-measured for the front door and it was 4' off. Extremely difficult to fix. This is the fault of the contractor not ICF, but is to point out the difficultly in making changes if changes need to be made. I looked into doing ICF but no one around at the time was proficient in doing it.

I've only seen it done with a slab, so some things to watch for:
- The slab where the forms sit needs to be clean so the concrete will bond with the slab.
- There's a good chance the electrician will only cut the foam to run the electrical lines. Not sure this will meet code for distance from drywall.
- I've been told that the plastic "studs" don't hold the drywall very well and some contractors will put a stud wall up for the drywall. Need to talk to your contractor about what he does.

 

[3Ts]

ICF is Insulated Concrete Forms. It's a Styrofoam block (similar to a concrete block) that is built up in a wall similar to lego blocks, then filled with concrete. It makes a very strong and energy efficient wall.

 

[CADplans]

Only two ways I would consider ICF,,
1) if it were a DIY,,,
2) if I found a VERY experienced crew to do it,,

ZERO percent chance I would contract it to a crew that had never done it before,, TOO MUCH learning curve,,

If I were to DIY,, there would be no one to blame, what ever the DIY result was,, I would be happy with it,,,

 

[Diggin It]

Ah, OK. I've seen pictures, but never worked with it, but my situation may be similar enough to be of some value.

This house is concrete block. There was zero insulation anywhere. I added 1 1/2" of pink board to the outside between vertical 2x4s TapConned and glued to the block, then vinyl siding. Inside, I added another 3/4" of pink board, then drywall. I didn't even try to run any wiring under or though any of that which would seem to emulate an ICF type wall.

I opted for Wiremold 4000 series surface raceway on the face of the drywall. That gave me two channels by using their dividers, one for high voltage (110VAC) and one for low voltage (telephone, computer and Coax/Video). A wide range of faceplate adapters are available for outlets or jacks. Mounted about 15" above finished floor, it's hidden by most furniture, etc., but is still easily accessible for modification as necessary. It's not exactly 'cheap', but is very versatile and easy to install. Adding wires is a breeze if new circuits are desired.

 

[duffer]

I built my last 2 houses with ICF's. My brother and I did the install of the blocks, then hired an expert contractor to do the bracing and the pour. I used polystyrene forms vs the Nexcem you're looking at. Nexcem wasn't even available 10 years ago when I did the 1st house. I know, because I went to 2 Int'l builders shows, 2 years in a row, and never saw them. Saw 47 other ICF manufacturers, but nothing using Nexcem type materials. Not saying they aren't any good, just uncertain that their product hasn't had a history of proven performance yet.

I looked at the Nexcem website to learn about them, and while they may be satisfactory, I have some concerns that you might want to consider:
* The Nexcem product appears to have much "thinner" walls on the block than poly ICF's. Means less R value (confirmed on their website) and probably requires more bracing during the concrete pour than poly ICF's.
* I question the "load" the exterior of the form to carry the weight of cabinets filled with dishes. The website says you can screw anywhere on the form, which implies flexibility of subsequent materials hanging on the wall. Based on my review of their construction and materials used in the forms, I doubt the exterior of the form will hold anything but a picture. And do they require tap con screws vs drywall screws? Mortar is not a substantial load bearing material. It is a bonding material when wet. Chips away easily when dry.
* Their forms are much smaller than poly forms, meaning you have more blocks, and more labor to install them. Thus more $$$. Typical poly forms are 48" long x 16" high x varying depths based on your needs. Nexcem blocks are 24"-36" long x 12" high x varying depths.
* I don't care for their engineering of the block to hold rebar, which is an essential element to a strong wall. In their blocks the rebar will definitely bend, and move during the pour, giving you inconsistent strength throughout the finished wall.
* From their website it looks like there are only 2-3 attachment points when stacking the blocks. Poly blocks have 40+ on a 48" long block. Means you'll have lots of "minor leaks" with Nexcem during the pour with 8 slump, and likely a lot of concrete stains and runs on the inside and outside of the Nexcem forms. If you're planning on having any of the inside walls left "naked", I suspect you won't like the looks of the wall. And you have an increased probability for blow outs during the pour.
* ALL ICF forms require pre-planning for elec runs, wall conduits for mechanical hook ups, etc. Cutting a 20-30' channel for elec in each room with the Nexcem block will be like being caught in a dust storm in Iraq. Have you ever cut a piece of Hardy board? It's roughly the same type of material. It's a mess. Cutting a poly form is easy. I used an elec chainsaw to cut the channels. Romex fit in nicely in the channel and the styro secured it by friction.
* I'm not saying Nexcem isn't a good block, but you'll be hard pressed to find a good-excellent installer. And believe me, there are numerous tricks of the trade to get a really good install. (too many to list here) I'd suggest you talk to at least 2 if not 3 installers to discover their skill level and knowledge of installing THIS block (not poly block). Because I suspect many installers will have poly block experience, will assume they can install this type of block the same way. I beg to differ.
*Every building product has its own trade-offs. Poly forms have their own drawbacks. You just have to know what they are and can you compensate for them (like elec channels, and location of conduits for mechanical hook ups thru walls)
* The Nexcem R value is far less than a comparable poly ICF form. My walls (6" concrete internally) are R-50.

Please understand....I'm not poo-pooing the Nexcem block. I've never seen it up close and personal. But from the website pictures, descriptions, etc, these are the concerns I have on the info provided.

Sorry this is so long of a post, but "you asked for it"! :thumbsup:

 

[dalola]

I used the blue-max ICF system and have been happy with it.

If I build again I would go to the roof with ICF and use SIP for the roof. Think Thermos-Bottle.

Blue-max uses plastic studs 8 inches on center and drywall is a breeze to install. The negative is that if you drywall directly to it you have to cut channels for the electrical so pre-planning is required and if you hire electricians you will have to put up with their whining. If I build again I would install EMT or conduit traces to make later retrofits easier as you can't snake wires through the finished walls on ICF.

Hire a good experienced contractor with the right equipment/supports to install. Get the wrong guy and you will have wonky walls and possible blowouts during the pour. I wouldnt attempt doing a one man install, just too much going on during the pour.

ICF Pros: very good insulation and sound deadening, tornado proof, thermal mass means cooler in summer and warmer in winter, stable wall system (ie. no wood shrinkage), add triple glazing and you end up with a very quiet house, easy to have high ceilings without large added costs, air-tight and energy efficient

Cons: more expensive up front, need skilled labor to install, electrical and plumbing stacks need pre-planning, listening to contractors whining because the cant blow holes wherever they feel like it. You will need an ERV/HRV because of the air-thight construction

I've heard a lot of horror stories about bad installs by inexperienced contractors and bugs moving in ie. ant colonies moving into the foam. I've been in it for 20 years and, knock on wood, have had no such issues.

Here's a good quote for you to consider - 80 percent of the building's cost over its lifetime is in the day to day operation for things like heating and cooling - only 20 percent is the actual construction cost.

Spend your money upfront on insulation and good planning and you will save in the long run with low living costs and comfort.

Google Passivhaus and passive solar design.

Have not researched Blue-max, will look into it. Agree with most of your points.... I would also go 100% ICF to the roof. Not looking to DIY this, but want to be heavily involved. From what I've gathered so far, it seems ICF might add 5-10% vs std stick build. Seems more than worth it to me.

You will need to be there when they set the forms. My neighbor did an ICF and they set the forms and poured while he was on vacation. They mis-measured for the front door and it was 4' off. Extremely difficult to fix. This is the fault of the contractor not ICF, but is to point out the difficultly in making changes if changes need to be made. I looked into doing ICF but no one around at the time was proficient in doing it.

I've only seen it done with a slab, so some things to watch for:
- The slab where the forms sit needs to be clean so the concrete will bond with the slab.
- There's a good chance the electrician will only cut the foam to run the electrical lines. Not sure this will meet code for distance from drywall.
- I've been told that the plastic "studs" don't hold the drywall very well and some contractors will put a stud wall up for the drywall. Need to talk to your contractor about what he does.

For sure I'd want an experienced contractor. Easy to see where things could go south in a hurry for the careless/clueless.

Only two ways I would consider ICF,,
1) if it were a DIY,,,
2) if I found a VERY experienced crew to do it,,

ZERO percent chance I would contract it to a crew that had never done it before,, TOO MUCH learning curve,,

If I were to DIY,, there would be no one to blame, what ever the DIY result was,, I would be happy with it,,,

I could see DIY for someone with way more experience than me! As mentioned, I want to be involved, but only with an experienced ICF contractor. I suspect that will be the issue....finding a quality experienced contractor. Doesn't seem to be any of that style construction around here.

 

[Industrial Toys]

A friend built a house this way. Had one blow out in the basement. I would have been pissed! I helped wire the place, and it's a horrible process. A chainsaw and styrofoam don't go well together.

I do a lot of low voltage wiring. Not much chance of running anything in exterior walls after the fact.

BUT, he loves the finished house for it's ability to stay warm or cool.