Crawl Space Insulation - Radiant Barrier
In some cases, radiant barriers are installed on the underside of the floor joists, with fiberglass insulation above them. The idea is that the barrier will reflect heat back into the house in the winter and down into the crawl space in the summer, in an attempt to keep the home comfortable. However, Radiant Barriers need to be shiny to reflect, and the dirt and dust in the crawl space, mean the barrier will not stay shiny for long. They also require an air space on either side to be effective, the side facing the insulation does not have enough of an air space to do its job. These barriers also allow moisture to get trapped between the barrier and subfloor, not allowing the insulation or joists to dry out.