Frost-Protected Crawl Space Construction
I am planning to construct a frost-protected footing/stemwall for a crawlspace in the northern Illinois region. Based on IRC guidelines, I only need to provide vertical insulation on the foundation wall to a minimum depth of 14 in. (depth to top of footing). Based on this, I have two general questions:
1. If I only need to provide vertical insulation, can I install it on the inside of the foundation wall instead of the outside? The commentary for ASCE 32-01 states that “vertical insulation may be placed within a perimeter wood foundation or … on the interior and exterior of a perimeter grade beam (ICS) provided there are no cold bridges between the interior of the building and exterior of foundation wall.” It would seem that the insulation could be entirely on the inside if there are no cold bridges as noted.
2. With such a shallow depth to the footing drain, I was considering extending gravel all the way up to grade and creating a perimeter gravel bed around the foundation. This would not allow drainage away from the foundation wall, but would that matter if any water could drain right down to the footing drain?
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