FAQ Insulation & Vapor Barrier

Q.  What are the insulation R-values that I need for my home?

A.  At minimum, the walls require an R- 21, the ceiling must be R-38 and the foundation and rim boards must be a minimum of R-10.

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Q.  How thick should my vapor barrier be?  Should it be hung tight?  Do I need to use tape and /or acoustic sealant?

A.  The vapor barrier must be at least 6 mils in thickness.  It should be hung neatly with some slack in the corners.  Tight corners cold tear when the sheetrock is hung and/or as the vapor barrier shrinks.  The use of tape is required when there is a seam that is not backed by framing.  This typically happens when the seam is placed at right angles to the framing.  Acoustic sealant is not required but is recommended.

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Q.  Can I use spray foam in the crawl space and attic?

A.  Yes; however, any exposed spray foam or some brands of rigid insulation must be protected with a fire barrier such as fiberglass insulation, sheetrock or sheet metal.

Category: Building Department