Why R10 but not R20 for Basement Wall in MA

Discussion in 'Remodel Forum & Blog' started by lmei007, Feb 4, 2012.

  1. lmei007

    lmei007 Member

    Sep 21, 2007
    I thought the recommended basement wall R-value is 20 but just found the government's recommendation for interior wall is R10 but not R20 for zone 3. Form the zone map, it looks like MA is in zone 3.

    does the R10 recommendation assume there is a good exterior insulation? or R10 itself is enough for interior wall no matter the condition of wall exterior insulation.

    I have a full basement with window wells. It only have about 7" above ground. It requires less insulation for underground wall, I think. If R10 is enough, I can save some money which is planned for fibre glass batts.

    Bying using this calculator, http://www.ornl.gov/sci/roofs+walls/insulation/ins_16.html, I got R11 or R15 in my area with 018XX, 024XX and 017XX zip code. It seems R20 is overkill?

    Dana, I know you have done yours with R20. What's your opinion about this?
Similar Threads: Basement Wall
Forum Title Date
Remodel Forum & Blog Finishing Basement - Doubling the wall insulation Mar 23, 2017
Remodel Forum & Blog Basement closet wall with foam needs drywall for fireproof? Jun 4, 2016
Remodel Forum & Blog Finishing basement: Floor and Walls Jan 27, 2015
Remodel Forum & Blog Basement floor & wall insulation with perimeter drain Jan 21, 2015
Remodel Forum & Blog Advise asked on basement wall insulation and fire blocking Jan 15, 2015

Share This Page