modify standard foundation wall and footing to shallow frost protected foundation

[madcowscarnival]

Spoke with a potential client today. Am seeking some suggestions for direction to proceed.

Situation. Standard rectangular house, 8' foundation wall on 8"x16" footing. Owner wants to significantly regrade the property and create a walkout area on the rear foundation wall. This area has an air freezing index of 1000 putting it at the minimum insulation requirement of the table. No horizontal, 12" minimum vertical (more than minimum will be used however).

Question: Height of footing is 8 inches, the top of the interior slab is 4 inches above the top of footing. An exterior patio would be constructed to match interior FFE. The vertical insulation would not be continuous and would jog over the footing: does this meet the intent of the code? Can high density foam be exposed to elements, i.e. between the exterior patio slab and the foundation wall? What options would there be for protecting that exposed edge? Maybe furring strips with siding on the exposed wall and flash over the insulation?

 

[dik]

Some foams have UV inhibitors; it's normal practice to provide a covering to the insulation so it is not exposed.

Dik

 

[oldestguy]

Here in Wisconsin it is common to ether place a Masonite type cover over exposed foam board or paint it with some form of cover like a plaster paint. Some of that paint works fine, but others peal off in time.

As to your slab outside, I's set that on 2" or better foam board, closed cell, to at least 4 feet out. Elsewhere I'd bury some of that board some and have that extend out from the footing at least 4 feet. You want to make the cold travel at last 4 feet before it gets to a footing.

I did these treatments for an added exterior entrance and it has worked fine for about 7 years now.