Encapsulated crawlspace conditioning with necessity for isolation
The final task I have before moving in is to encapsulate my crawl space. I’ve read all the usual GBA articles, but in my situation there are some additional factors to consider.
1869 house with a low crawlspace. Was full of asbestos, but was abated. The area is so cramped, it’s almost guaranteed it wasn’t 100%. In addition to asbestos, it’s full of general nastiness I want to keep out of my house.
My plan was to use a combination of polyiso and rock wool to insulate and seal below the main level floor. Then I’d hope to spread 6mil poly sheet for a vapor barrier and seal to rim joist area (balloon framing) with spray foam.
Now I need to prevent stack effect from sucking up into living area. I assume my best bet is vent to outside from rim joist area with 50-70cfm fan and cut an access grate in main level floor?
Opening the floor to connect to crawlspace is not overly appealing, even if air will hopefully be negative pressure down below. I seriously considered going old school vented… I have a newborn baby so any help appreciated.
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