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Join Date: Jan 2010
Location: Wexford, Pennsylvania 15090
Re: Camp crawl spaces- question on sealing?
First of all, I hate crawl spaces. I do a lot of insurance investigations of rotted framing over insufficiently vented crawl spaces. The code requires one square foot of net free venting area (NFVA) for every 150 square foot of crawl space. Vents should be located to provide cross flow and one vent within 3 feet of each corner. A typical 8 x 16 louvered block vent provides about 64 square inches of NFVA each. The venting requirement can be reduced to 1 square foot for every 1500 square foot of crawl space if you use a vapor retarder with sealed seams and sealing of the barrier to the stem walls. You also need a drainage system to prevent the accumulation of water. I also recommend insulation around the perimeter to prevent warmer air from condensing on the cold exterior walls. As mentioned above, mechanical venting is an option, but if used, should run continuously. Did I already mention that I hate crawl spaces?