I have what you may call a crawl space underneath an enclosed porch. The only way I can get in is through the flooring. The area is 6 feet x 3 feet x 6 feet.What would be the simplest way to insulate this area? Should I install blown insulation or go in and put foam-board up? I do not know what the space is like.

expert EXPERT April 26, 2007

In a space the size that you have described, we would recommend insulating the underside of the floor. Foam board could be used, however it is combustible and therefore should be covered with something noncombustible. Foam board is also very easy for vermin to chew through. Another good reason for covering it, if there is potential for vermin to enter this crawlspace. Alternatively, batts of insulation could be installed, and held in place by chicken wire or building wrap. Again, you may want to consider something more substantial as a covering, if there is potential for vermin. Also, the floor area should be covered with heavy polyethylene (six mil), if it is earth. This will significantly reduce moisture in the crawlspace. The plastic should be covered with some sort of ballast, to protect it and keep it in place.