Re: Concrete/Foam Structural Insulated Panel
An uninsulated 8-inch-thick basement wall built using normal-weight concrete has a R-value of about 1.35.
By doubling the thickness of the wall to 16 inches, the R-value only increases by 0.50 .
It's the ICF that provides the insulation R value and not the concrete.
I'm not sure if I understand the question .... if you require an 8 inch thick concrete wall then you will still have an 8 inch thick wall using flat panel ICF.... generally no concrete savings.
In a very broad-brush comparison, I'm wondering how much concrete material, as thickness of the wall, is saved by using ICF's.
The foam panels are merely used as the forms for casting the concrete ... they remain in place and happen to provide a good insulation value.
However ..... there was an ICF designed to form a series of post and beams in the casting instead of a single thick slab resulting from the flat panel ICF.
This type apparently used 25% less concrete .
Hopefully this helps.
"" an ounce of perception -- a pound of obscure "