What's the best type of insulation to use in a basement?

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Answered by Tim Snyder, Guest Editor

Let’s begin this answer with the insulation that shouldn’t be used in the basement. Fiberglass batts and cellulose insulation are bad choices. This fluffy insulation will absorb and hold moisture, which can cause the material to compress, fall out of place and lose R-value. The best way to insulate the basement is to install rigid foam insulation against basement walls. Small rectangles of rigid foam insulation can also be wedged between floor joists and against the rim joist to insulate the rim joist area. When the foundation walls have an irregular surface, like stone walls, for example, a good insulation treatment is to cover the inside wall surface with 2-part spray polyurethane foam (SPF).

About the author: A journalist specializing in sustainability, energy efficiency and home improvement topics, Tim Snyder is a former executive editor of Fine Homebuilding and American Woodworker magazines. Tim's recent work includes a green remodeling manual for the Environmental Protection Agency, and a chapter on “Smart Shelter” for The Whole Green Catalog. Tim’s blogs and web content can be found at myHOMEscience.com, DrEnergySaver.com,BasementSystems.com, MotherEarthNews.com, Wisebread.com, Green-Energy-News.com, RealtyBiznews.com and other sites.