Siding choice for a ICF home
With our ICF home, we originally planned to use EIFs on the exterior. I understand that there is minimal risk of the problems that wood structures experience with EIFs. However, as a spec builder we need to be sure that buyers are not being turned away by uneducated home inspectors and I think this issue maybe a distraction from a sale. I also just called Geico to find out the insurability of such a house, they told me that out of the 6 underwriter in our area, 4 would categorically reject any home with EIFs siding regardless of ICF construction.
If I were to ditch EIFS, what options do I have? I understand there’s true stucco, which I think may cost too much in terms of labor and I like wood lap sidings but the material costs are higher.
For those of you, who are more experienced in this area, what would you suggest? Just to add some limitations, the ICF walls will have 2.5″ of EPS foam that’s part of the forms and about 3-4″ of EPS on the outside to beef up the R-value.
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Replies
Roger,
Just because your house is made of ICFs, does not mean that there is any limit to siding choices. You can choose any siding you want: brick veneer, stucco, cedar lap siding, fiber-cement siding, board & batten siding.
This is a personal decision, based on cost, the local style, and your own personal preferences.
Read more about siding in our encyclopedia:
Siding Choices
Thanks Martin.
Roger,
I have done several projects using both ICF's and vertically strapped rigid insulation, finished with fiber cement siding. For the ICF's, we fastened the siding over the weather resistant barrier into the ICF plastic wickets. Since there is 3/8" foam from outside face of ICF to wicket, the thinness of the siding results in a wavy siding surface, We have had similar results applying fiber cement siding directly to vertical strapping over rigid insulation. We have found that we get a straighter fiber cement wall surface when applied directly over sheathing.
In the Southwest (CA, NV, AZ, NM, UT, CO, etc.), commonly we use 2-coat stucco and usually we attach stone veneer as accents to it as well. It's very cost effective and gives great curve appeal.
Jon, when you wrote, "We have found that we get a straighter fiber cement wall surface when applied directly over sheathing", did you mean you put additionally sheathing on the ICF prior to fastening the fiber cement sidings?
Amando: I like the idea and the look but I am not sure if that'll fly in the D.C. area.
The house design is quite modern, which is why I initially wanted to do EIFs. I am still considering it but I am looking into maybe some sort of wood siding. Does anyone know how to get that very modern looking wood siding look that seems to be on every green building these days? What kind of wood siding is it?
With the 2.5" EPS on the ICF forms plus 4 more inches that we are planning to put on. I am thinking that I will need to attach furring strips onto the ICF plastic wickets, place the additional foam then attach the wood sidings on the furring strips?
Instead of stone veneer, use slate stone tile, exposed concrete, concrete block veneer, metal or glass claddings, etc for accents... There is plenty of modern buildings using all of those claddings. Just some thoughts...
Roger,
I worked on a project that is using EIFS over an ICF with extra outboard insulation. I still have ambiguous feelings about EIFS but it seems to be going well. The real test is how it will hold up in the years to come.
I have seen a less than attractive cement board lap siding over ICFs that would make me hesitate to do it in my own projects. Unevenness was one concern, another was an odd exposed fastener here and there which may have been more about the installer but I interpreted it as some odd spots due to the spacing of the nailing flanges on the ICF.
Your windows will likely be set back towards the concrete layer of the ICF. You'll want to work out your window/door return, header, sill details on paper on not have that stuff figured out by installers in the field.
Roger,
With the fiber cement lap siding fastened directly over ICF's we got a wavy wall. So much that next time I would apply a sheathing over the ICF's, then weather resistant barrier and lap siding. We got similar results with 5/16" horizontal lap siding directly over vertical furring.
Rather than adding sheathing and then 5/16" lap siding, you could choose a thicker and more rigid siding. For fibercement there's Hardie Artisan lap, or use wood siding. But to the original question about EIFS, I don't think much can go wrong when the rest of the wall is as water tolerant as ICF.