Protecting Above-Grade ICF Foundation
Hi there. My husband and I moved into our newly built energy efficient house about a month ago. We live in Zone 5 and have a slab-on-grade foundation. Our stem walls were built using ICF.
Recently, while researching landscaping ideas, we discovered that it’s best practices to protect ICF that is above grade from UV light and physical damage. Not only that, but our local code states that it needs to be protected above grade and go down at least 6 inches. (We actually asked about it during construction because exposed ICF just looks wrong, but we were confidently told is was fine as is and didn’t look in to it further.)
For what it’s worth, our local code does not require damp/waterproofing on below-grade insulation/ICF unless there is “inhabitable space” on the other side of the wall. Since that does not apply to us, there is no waterproofing below grade, either. There is supposedly a termite shield installed. We do not live in an area that requires below-grade termite protection.
Long story short, our architect did not include the protection detail in the drawings, the contractor didn’t bid / do it, and the city did not catch the code error. (The architect admitted she made a mistake, but that doesn’t solve our problem.)
So, our house passed inspection, we are living there, and everything has been backfilled for ages. The foundation and slab were originally poured in late July / early August if memory serves. Our siding is galvalume corrugated metal siding, if that matters.
At this time, our contractor has essentially washed his hands of us, and I’m not sure we can use him as a resource anymore.
I think it’s obvious that we need to figure out a way to protect it as soon as possible. I have read the articles on GBA and elsewhere and see the most common way is parging. My question is this:
1. Is this something that my husband and I could do on our own, or is it too risky? We have no experience but we are detail-oriented and can follow directions. Our house is 1400 square feet, so it’s not huge.
2. If we need a professional, who do we even call to get a quote? A concrete contractor?
3. Is there anything else we should be aware of as we try to solve this? (E.g., we are totally screwed because the siding is on, etc.) We live near the Indiana Dunes and our “soil” is essentially all sand, if that matters (it is much easier to dig in sand . . .)
Thanks in advance. We thought we had successfully built a house and, turns out, we didn’t. Any advice/insight would be HUGELY appreciated.
-J
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Replies
I would contact the ICF manufacturer regarding the lack of waterproofing, even with slab on grade.
For protecting the above grade portion, I would consider Boral’s Tru Exterior trim. It is a poly ash composite that is rated for ground contact. This may be easier to do yourself vs parging.
If the amount of exposed ICF foam is not that much, you can also look at covering it with coil stock. A local roofing or sheet metal shop can bend it to tuck into under the siding and run it down to grade. The bottom will rust overtime, but this will take a very long time.
If you can find the right color there is also PVC trim (stock/coil) you can use. I've also used composite deck board facia board panels for ground contact trim, not cheap but take a lot of abuse.
Thanks for your response. Do those things need to be physically attached to the insulated form? Sorry if that is a stupid question . . . I'm guessing the answer is "yes." We are afraid of attaching things as nonprofessionals and damaging things further. The troweled-on stuff somehow seems less intimidating.
I have been trying to find ICF contractors in my area all afternoon and I can't seem to find any. Perhaps I'm searching for the wrong thing. But I'm trying to plan for worst case scenario: This is something we have to deal with ourselves because there is literally no one to help us.
If you are DIY'er types, you can parge it yourself.
Otherwise, if you want to hire it out, you could hire laborers to dig a trench around the house 6-8" below grade, then hire a retired mason to parge it. Have the mason start in an inconspicuous area so you can check the quality and the parge pattern (some get a swirly pattern, some a non-directional stucco look, etc.)
I think I would be most concerned about ensuring and understanding the termite barrier. In many areas of the country it will when do you get termites, not if...
Thank you for your reply and good call re: termites. We have a termite shield in the drawings, but I need to confirm it was installed. That was something I "trusted" happened, but given what has happened thus far, I need to confirm.
Apparently termites can't move through sand well, and we are on 100% sand. But I will definitely look into what has been done and what needs to be done. They are one of the reasons I'm freaking out about this.
I used "Tuff II", which is a troweled on elastomeric coating. Much easier than parging and is relatively thin. It is applied over a self-stick mesh that also is easy to install. It has now been on my house for 5 years, holding up great. BTW, I also have corrugated metal siding.
I think I watched a video of someone installing this product (or a similar one). That's what made me think "oh, maybe I could do this myself." Did you do yours yourself?
Thank you for replying and go corrugated metal siding! We love ours.
These are informative:
https://www.greenbuildingadvisor.com/article/how-to-finish-exterior-foundation-insulation
and
https://www.greenbuildingadvisor.com/question/foundation-foam-finish-acrylic-vs-cementitious