insulation - DIY Chatroom

joan518 · 10-30-2009, 01:02 AM

I have a 32x40 ft. basement with 9' ceiling height, most of it is in the ground only about 3' above grade and one 20' walkout part. The exposed walkout part has insulation poured inside the block. The block are 12" and are covered by manufactured stone on walk-out part and above grade on rest. One side has a crawl space attached. My question is should I insulate the ceiling or not? It stays a pretty constant temperature of about 20 degrees warmer in winter and 20 degrees cooler in summer. Also I have a fireplace in the basement that I use sometimes, since heat rises, wouldn't the warmer temp. in the basement(with or without fire in fireplace) help heat the upstairs and would I be losing this advantage if I insulate the ceiling or will I just have cold floors if I don't. This is new construction and I haven't lived there yet to find out. I need to know before drywallers come as they will be drywalling basement ceiling. Thanks!

Bob Mariani · 10-30-2009, 04:52 AM

insulating the ceiling of a finished basement is not needed if this basement is to be a conditioned space. It is more important that you insulated the rim joist and the space between each joist along this rim joist with spray foam insulation. (now heated air will rise to help warm upper floors) Another approach is to insulated the ceiling so the zoned heat and/or cooling of the house is isolated. Now if the heat is not used in the basement but needed in floors above the insulated ceiling will help cut energy costs.

CustomBuild · 10-30-2009, 05:50 AM

I agree with Mr. Mariani. Also something to consider is sound transmittance. While insulation will not prevent sound from travelling through the floor, it does muffle sound and helps that "hollow floor" feel.

joan518 · 10-30-2009, 12:11 PM

Thanks, good point about insulating the spaces between the joists around outside as this is above grade. Thanks for the tip about sound , that is something to consider, as well. Thanks a lot ! You have been a big help.

GBR in WA · 10-30-2009, 08:40 PM

How now: http://www.rd.com/57548/article57548.html
Be safe, Gary

joan518 · 10-30-2009, 09:13 PM

Thanks for the site.

diy'er on LI · 11-06-2009, 06:05 PM

Quote:

Originally Posted by GBR in WA

How now: http://www.rd.com/57548/article57548.html
Be safe, Gary

that's a great link! Explicit instructions with step by step photos... Thanks! As soon as we have paid off our current project, we'll jump into that one!