Vapor Barrier

The International Residential Code (IRC) and the International Energy Conservation Code (IECC) now eliminate the requirement for vapor barriers for frame walls, floors and ceilings in Climate Zones 1 - 4.

(Crawl space floor vapor retarders are not exempted.) 

Residential Insulation does not recommend the use of vapor barriers when used with cellulose insulation except in high concentrated moisture areas, such as spas,  restaurants, pool buildings, etc.

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