Insulating Concrete Columns
tecbuilt
| Posted in General Questions on
I am building an ICF house where the ground floor will be slab on grade with hydronic radiant heat. I will put rigid foam insulation under the slab as recommended but there are a couple concrete columns on footings (interior to the house) that I need to deal with. I am planning on having insulation between the slab and the column footings but not sure what to do with the column itself. Do I wrap the whole column in foam board insulation all the way down to the footing and then put a cover over the insulation (sheetrock, cement board etc.)? I haven’t been able to find much information on this subject. Thank you for your time.
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Replies
Wrapping a circular column in foam board will be hard to do without making it a square column. I wouldn't use sheetrock or cement board to protect the foam. You are better off using a synthetic stucco/parge coat on the foam to provide protection for the foam.
I should have specified the column shape. They are 16" square columns sitting on 5' x 5' x 18" footers. I really have 2 questions, one since they are interior columns do I need to insulate the sides of the columns or is the heat loss small enough not to worry about and two if I do need to insulate them what is the best method to do so?
Are the footings completely below slab level?
What is the local subsoil temperature?
Are there specific performance requirements you're needing to meet?
The column footings are deep enough to have rigid foam between the slab and the top of the footings. Local subsoil temperature averages about 47 degrees. Just trying to understand if I am going to lose a significant amount of heat to the column if it isn't insulated and if so what is the best way to insulate the column.
Make sure you've allowed for the load on any rigid foam going under a column. Columns present much more concentrated loads than a slab, so you may have to use one of the specialty high-strength foam boards here. I would also make sure to put reinforcement in the footing to ensure that the load is spread out without cracking the concrete footing.
Bill
I wasn't planning on putting rigid foam under the column footings because of load requirements so just wondering what is the best way to keep from losing heat into the column. I'm thinking of just putting an expansion joint between the slab and the column and calling it good.