ICF House

[Xander]

I don't know who here has built or added onto their homes but I thought people might be interested in how I built my house. I used Insulated Concrete Forms (ICFs) to stack and build like legos. Here are a few links

wiki aritcle [ame="http://en.wikipedia.org/wiki/Insulating_concrete_form"]Insulating concrete form - Wikipedia, the free encyclopedia[/ame]

pictures http://www.google.com/search?q=insul...w=1346&bih=700

I built it a few years ago and I am still finishing areas or adding more floor space in the form of a bonus room in the garage. The advantage is the lower utility costs. This savings is offset by the higher construction cost which last I calculated would take me 15 years to pay back with lower utility costs. Part of that is the low cost of gas and electricity in Utah. In other areas of the country it would work out differently. So it is definitely not for everyone.

Here are a few pics of the construction.

stacking the blocks



pouring the wall


finishing the second pour


putting hydronic tubes in the basement slab (i.e. radiant heat)


upper floor tubes in place. pours a thin slab of concrete (1.5 inches). Blocked out the place were the walls were going to be for a screed layer, as well as to run electrical and plumbing into the basement. Easier to cut through wood then concrete.

Anyway I learned a lot building it. It prematurely aged me a few years but I survived.

[Surfah]

Very cool. I am curious as to how you finish the exterior and interior walls and what materials. Do you have to put a moisture barrier on the exterior walls? The roof I assume is a wood truss? How does the R-value compare to a stick framed home?

[pellegrino]

If I ever build a house (which I doubt will ever happen) I will choose ICF construction in a heartbeat.

[Jeff Lebowski]

Very cool.

[Xander]

Very cool. I am curious as to how you finish the exterior and interior walls and what materials. Do you have to put a moisture barrier on the exterior walls? The roof I assume is a wood truss? How does the R-value compare to a stick framed home?

The exterior can be anything. The easiest is stucco because of the Styrofoam base. You just do a scratch coat then the colored coat and your done. No wire mesh just a vinyl mesh. You'll notice in the first picture the brick ledge block is on and is wider than the normal block. Once the wall is built you just start laying your brick, no different than a traditional foundation at that point.

As for siding or interior Sheetrock, they have plastic ties that you screw into that are imbedded 1/2 inch from the surface and they occur every 8 inches but that varies by block manufacturer.

The R value based on the Styrofoam is r-5 per inch. So if you include the interior and exterior Styrofoam that comes out to about R-28 . But you also have to include the fact that there is concrete in the middle and no air infiltration. This adds to the overall efficiency.

The only moisture barrier you need is on the foundation where it makes contact with the ground. The roof is a standard wood truss.

[pellegrino]

The exterior can be anything. The easiest is stucco because of the Styrofoam base. You just do a scratch coat then the colored coat and your done. No wire mesh just a vinyl mesh. You'll notice in the first picture the brick ledge block is on and is wider than the normal block. Once the wall is built you just start laying your brick, no different than a traditional foundation at that point.

As for siding or interior Sheetrock, they have plastic ties that you screw into that are imbedded 1/2 inch from the surface and they occur every 8 inches but that varies by block manufacturer.

The R value based on the Styrofoam is r-5 per inch. So if you include the interior and exterior Styrofoam that comes out to about R-28 . But you also have to include the fact that there is concrete in the middle and no air infiltration. This adds to the overall efficiency.

The only moisture barrier you need is on the foundation where it makes contact with the ground. The roof is a standard wood truss.

yeah, and if you sprayfoam the roof you get even better efficiency

[Uncle Ted]

So I am guessing that the concrete is pumped in layers creating a lot of cold joints. I have seen a lot of tilt up concrete wall construction going on (mainly commercial) and wonder if that would be better. Concrete is not my thing so I don't know.

[Xander]

So I am guessing that the concrete is pumped in layers creating a lot of cold joints. I have seen a lot of tilt up concrete wall construction going on (mainly commercial) and wonder if that would be better. Concrete is not my thing so I don't know.

There is one cold joint, as I poured it in two pours. Its overlapped by 2 feet of rebar every 16 inches so it shouldn't be an issue. I also vibrated the hell out of it with a stinger internally and an exterior vibrator, run up and down the wall several times. That settled the concrete several inches and I had to refill the forms to top them off.

[Xander]

yeah, and if you sprayfoam the roof you get even better efficiency

At some point you have to draw the line when it comes to efficiency. It keeps on adding more cost. Most people draw it at 2x4 construction. Some 2x6. I went a little further but everyone has there budget to consider. Although I've never heard of sprayfoam in the attic, I've only see blown in. People sprayfoam their walls though.

[Surfah]

At some point you have to draw the line when it comes to efficiency. It keeps on adding more cost. Most people draw it at 2x4 construction. Some 2x6. I went a little further but everyone has there budget to consider. Although I've never heard of sprayfoam in the attic, I've only see blown in. People sprayfoam their walls though.

Mike Holmes on HGTV sprayfoams the shit out of everything. That may be a Canadian thing though. Because I have seen several of those other TV contractors do it too.

[kccougar]

There's a commercial building going up on the NE corner of 1300 East and 2100 South in SLC that is ising ICF construction. Very uncommon process for this area.

[wuapinmon]

Mike Holmes on HGTV sprayfoams the shit out of everything. That may be a Canadian thing though. Because I have seen several of those other TV contractors do it too.

I wondered about that too, maybe it's just so much colder there that they have to worry about stuff.

[Xander]

Mike Holmes on HGTV sprayfoams the shit out of everything. That may be a Canadian thing though. Because I have seen several of those other TV contractors do it too.

I would think sprayfoaming directly onto drywall would be a bad idea. The way it expands and then the moisture might cause issues. If you were to sprayfoam into the attic I would think it would have to happen right under the roof.

[FN Phat]

There is one cold joint, as I poured it in two pours. Its overlapped by 2 feet of rebar every 16 inches so it shouldn't be an issue. I also vibrated the hell out of it with a stinger internally and an exterior vibrator, run up and down the wall several times. That settled the concrete several inches and I had to refill the forms to top them off.

You weren't worried about segregation?

Very impressive building methods. Was the cost of the ICFs much higher than a traditional concrete foundation? You save labor hours from not having to strip, clean, and stack forms. Or was that offset by the labor associated with installing the product?

[pellegrino]

At some point you have to draw the line when it comes to efficiency. It keeps on adding more cost. Most people draw it at 2x4 construction. Some 2x6. I went a little further but everyone has there budget to consider. Although I've never heard of sprayfoam in the attic, I've only see blown in. People sprayfoam their walls though.

I just had my attic sprayfoamed a week ago. It makes sense for us because the attic was never intended to be vented and we have our AC unit up there too. Temperatures here haven't been as hot as they usually are since it was done, but our AC unit has been running a lot less and when it does turn on the air is cold from the start. We have it at 76 from around 11:00 PM until 6:00 AM, and 79 during the day. Needless to say, it comes on around two or three times during the day for about five to ten minutes each time and then it kicks on in the evening for about a half hour.