Correct way to detail crawl space walls
I have a 100 year old Townhome in Alexandria, VA. One of the first things I did when I moved in was to put down a 20mil plastic membrane and a dehumidifier in the dirt crawl space. The membrane terminates a couple of inch from the top of the brick wall and attaches with mechanical fasteners. Fast forward a couple of years and I have been reading that I should also insulate the walls (not the floor joist, which is what I currently have.)
My thought was to attach XPS to the exterior foundation walls which would insulate and act as a water barrier but unlike all the articles I see my walls are not smooth (it’s 100 year old brick!).
1) Is the above XPS idea workable? I'm guessing not.
2) If not is my only other option to use closed cell spray foam on the inside walls? My concern in doing this is that the clearance in the crawl space is only about 8inch (floor to bottom of floor joist) in about 2/3 of the area. Kind of hard to pull those spray foam tanks around in.
3) In either case do I need to cut back the plastic membrane so that it is not going all the way up the wall? In other words am I creating a moisture trap between the membrane and the XPS or spray foam?
Posted Wed, 08/28/2013 - 10:17
Edited Wed, 08/28/2013 - 11:01
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