A Spray Foam Manufacturer's Statement
Here is a spray foam manufacturer’s statement on their letterhead concerning open cell under floors:
- Not to be used in exterior application, crawl spaces and exposed to exterior elements.
- Likely moisture build up, wood rot, and possible de-lamination of floors. (Also demonstrated in A Study of 12 Houses in Southern Louisiana)
- Will void warranties.
- Closed cell is the proper product to use in these circumstances.