The home is still in the design phase. It was originally being drawn as a 2x6 wood frame construction but I am considering ICF.

As you can see in the picture there are trapezoid windows which get really close to the roof line and take up an entire wall area with rectangular windows below them, especially in the right corner of the home. I am wondering can an ICF pour still be done or are there too many windows that would prevent one from stacking ICF block and doing a strong enough concrete pour in that corner?

One can REMOVE the trapezoid windows and leave the rectangular windows in place, that would provide enough space to do a pour but the architectural design would change.

Any input would be appreciated...

It can be done in ICF, there are options available for the lintels.

Location is going to be a factor

Your local designer/engineer will deal with this

But to give you an idea, the lintels may need to be built to underside of sheeting so roof framing would be on inside or outside of wall not the typical on top.

Have the designer work with an ICF contractor and/or engineer. Another ICF advantage is how well stucco works with them, versus how unforgiving stucco and wood framing combine.

With that many windows, what are you trying to gain by using ICF? The insulation effect is lost with all the windows.

Posted By jeepster on 08 Dec 2011 09:25 PM
With that many windows, what are you trying to gain by using ICF? The insulation effect is lost with all the windows.

The photo shows the south elevation which has the most windows. I am utilizing passive solar so the south facing part of the home has the most windows. The north, east and west windows are very limited.

I can REMOVE some of those trapezoid windows if needed.

So you are saying that making this an ICF home is pointless?

Lbear, Very impressive and interesting design. I'm not a huge window fan myself but I wouldn't compromise the windows if they are important to you. I also wouldn't compromise and build with what I believe you refered to in an early post as the supposedly "tried and true" 2x6 approach. Better tried and warped after a few years or tried and gone after 50. You also make the point that 3/4 of your home has less windows so you can still make your home 7-10 times stronger than tried and true and much safer overall both to fire and storm. Regards.

Are those window lintels about 8' wide or so? That is easily workable and making them in concrete should contribute to the strength of the wall. You will most likely need an experienced builder to get this right in ICF because of the high slim columns. Good bracing.

Those horizontal beams will need to project out to support the rake eaves.

You might want to think about how high those trapezoidal windows sneak up to the rafters and maybe save yourself a little money on the windows. If they are too high up under the eaves, they will receive no direct insolation. Without that, what you are left with is scattered light and heat loss. If someone in your household is a fanatic about lots of light, the heat loss might still be an acceptable tradeoff, but I will point out that there is less light to begin with up under the eaves. Diminishing returns. The thing to do is to figure out the rest of your widows, as well as how far the eaves will project out to shield them from the high Summer sun and then use that to determine where you want them to top out. Any additional space left under the rafter can be filled with a sandwich consisting of 2X lumber with rigid foam in between, or your carpenter can build some box beams with minimal thermal bridging and shoot them full of foam.

Your lower windows might also want a little eyebrow to shield them from weather and, again, the Summer sun. Or, shades.

Posted By ICFHybrid on 09 Dec 2011 11:13 AM
Are those window lintels about 8' wide or so? That is easily workable and making them in concrete should contribute to the strength of the wall. You will most likely need an experienced builder to get this right in ICF because of the high slim columns. Good bracing.

Those horizontal beams will need to project out to support the rake eaves.

You might want to think about how high those trapezoidal windows sneak up to the rafters and maybe save yourself a little money on the windows. If they are too high up under the eaves, they will receive no direct insolation. Without that, what you are left with is scattered light and heat loss. If someone in your household is a fanatic about lots of light, the heat loss might still be an acceptable tradeoff, but I will point out that there is less light to begin with up under the eaves. Diminishing returns. The thing to do is to figure out the rest of your widows, as well as how far the eaves will project out to shield them from the high Summer sun and then use that to determine where you want them to top out. Any additional space left under the rafter can be filled with a sandwich consisting of 2X lumber with rigid foam in between, or your carpenter can build some box beams with minimal thermal bridging and shoot them full of foam.

Your lower windows might also want a little eyebrow to shield them from weather and, again, the Summer sun. Or, shades.

Yes, I believe the window lintels are around 8' wide.

The more I think about it, I believe removing the trapezoid windows would save me money in both window costs and in construction costs. Pouring the ICF wall would be MUCH easier if the trapezoid windows were gone, and it would also beef up the homes strength.

Will it affect aesthetics? A little but not enough to justify keeping them. Now the hard part comes, how to convince the wife that those windows need to go.

Here is the NORTH elevation. As you can see the other elevations do not have as many windows as the south elevation. Just one set of fixed or casement window on the 2nd floor and a casement window on the 1st floor where the kitchen sink is. As I mentioned before, I will most likely REMOVE the trapezoid windows and the SLIDERS are gone, both the window and door slider. Still undecided what type of door to use.

Here is the WEST ELEVATION:





As you can see, not that many windows on the west side either. The majority of windows are on the SOUTH side, for the sake of views and passive solar gain.

QUESTION:

1 - Can that 2nd story walk-out balcony be made in ICF or should that just be wood framed out? I am not talking about the deck floor itself but the part that "juts" out. If it was made in ICF I don't think those wood column poles would be able to support the weight of it.

2 - Should I reduce the window area on that 2nd floor walk-out balcony room? Maybe removing the 2 windows that are on each side of that sliding door?

Here is the EAST elevation. It is mostly just standing seam metal roof:

Nice looking place. Build it ICF, you won't be sorry. You don't sound in love with all the windows and they are expensive and not energy efficient....eliminate them.

Cantilevers don't work well with the heavy weight framing (ICFs). But a couple concrete columns will hold up a lot.

How would ICF handle the angled sloped roof line? Since concrete is self-leveling and you can't pour an angled concrete pour. How do you address that problem?

We have poured up to a 6/12 pitch without a form and more than than 6/12 by placing a form board on top of the wall.

Posted By ICFconstruction on 09 Dec 2011 10:03 PM
We have poured up to a 6/12 pitch without a form and more than than 6/12 by placing a form board on top of the wall.

I see, so basically the ICF is cut at an angle and then a form board is placed on top, which would prevent the concrete from seeping out.

How long (length wise) was the pitch?

One way to do it is to have your treated wood top plate cut in short sections, say 4'-6' long with J bolts pre-installed ~1' from each end (nut on both sides of the wood plate with the J hook extending down to be imbedded in the wet concrete). Have this top plate cut so that it just fits inside the forms, i.e. if you have 6" core ICF forms, rip a 2x8 (7-1/4" wide) down to 6" wide. ICF webs may have to be cut in places to allow placement of this top plate. When you get the concrete poured to the portion of the wall that slopes, install the first 4'-6' long section of top plate inside the forms flush with the top of the foam and use 4" long screws with EIFS plastic washers screwed through the foam into the side of the top plate every 8" or so to hold it in the forms. The hose operator can start filling that end of the gable while the guy installing the top plates goes to the other side of the gable to install the first 4'-6' section of top plate on that side. As the concrete is placed up to the top of this section of plate, continue adding sections of top plate until you get to the top of the gable.

Posted By arkie6 on 10 Dec 2011 12:38 AM
One way to do it is to have your treated wood top plate cut in short sections, say 4'-6' long with J bolts pre-installed ~1' from each end (nut on both sides of the wood plate with the J hook extending down to be imbedded in the wet concrete). Have this top plate cut so that it just fits inside the forms, i.e. if you have 6" core ICF forms, rip a 2x8 (7-1/4" wide) down to 6" wide. ICF webs may have to be cut in places to allow placement of this top plate. When you get the concrete poured to the portion of the wall that slopes, install the first 4'-6' long section of top plate inside the forms flush with the top of the foam and use 4" long screws with EIFS plastic washers screwed through the foam into the side of the top plate every 8" or so to hold it in the forms. The hose operator can start filling that end of the gable while the guy installing the top plates goes to the other side of the gable to install the first 4'-6' section of top plate on that side. As the concrete is placed up to the top of this section of plate, continue adding sections of top plate until you get to the top of the gable.

I found this pic on-line. Is this what you were referring to in the above?:



Notice in the larger pic, they are implementing an internal vibrating pencil.

Per the article:

Fabricating 12x12 pitch gables with concrete is tricky.  Many ICF homes avoid this step and revert to traditional wood frame construction because it is time and labor intensive.  For 60 Bragg Hill, the importance of the structural and thermal integrity of the home coupled with its architectural design mandated the gables be made of concrete and steel.

What makes this a tricky process is the inverted shape of the concrete mold.  As concrete is poured, the mold gets smaller and narrower making the dense mix a challenge to apply and agitate so that it settles correctly.  Like the other pours before, this was a carefully orchestrated ballet between the Thompson Builders (Mark, Mike and Matt) and Jody, Forcine’s 32 meter Putzmeister concrete pump operator.  This well rehearsed team delivered small bursts of number six slump concrete in the precise location at the right time.  Like a parfait dessert, a predetermined level of concrete was poured and settled in each gable cavity.  Then custom-built reinforced end caps were installed on the sloped edges of gables to define the mold for the next layer of concrete.  This process was repeated four times in a rotating sequence until the three gables were completely filled with concrete and sealed.

Posted By Lbear on 10 Dec 2011 03:51 AM

I found this pic on-line. Is this what you were referring to in the above?:

It looks to be similar to what I proposed; however, with the 2x6 (appears to me) attached to the sides of the ICF, it appears that their top wood plate is sitting flat on top of the ICF foam rather than inset into the forms like I described above.  The advantage of insetting the top plate inside the forms is that you now have ~2.5" of EPS foam on either side of the solid wood plate for insulation rather than a wood plate spanning from the outside edge of the wall to the inside edge of the wall.

If you want to go the underside of the roof sheathing, it is difficult to match the height of the top cord of the trusses, usually the trusses aren't up yet. Easier if the trusses are up and you fastener on to your gable end ICFs before you pour.

But most times on gable ends with a vaulted ceiling inside, and therefor scissor trusses, we will just get the ICFs above the bottom cord. Much more forgiving, less pitch and almost as good.

Posted By ICFconstruction on 10 Dec 2011 11:48 AM
If you want to go the underside of the roof sheathing, it is difficult to match the height of the top cord of the trusses, usually the trusses aren't up yet. Easier if the trusses are up and you fastener on to your gable end ICFs before you pour.

But most times on gable ends with a vaulted ceiling inside, and therefor scissor trusses, we will just get the ICFs above the bottom cord. Much more forgiving, less pitch and almost as good.

In another thread here he mentioned using 12" SIPS for the roof.  With SIPS I assume there would be a large ridge beam.  With the ICF gables, he would need to create a beam pocket at the peak to accept the ridge beam.  The ICF gables then would define the slope/pitch of the roof.