Insulating crawlspace and unfinished basement questions
I have an unfinished basement with 2 crawlspaces. The basement is in the center of the house. To the right (underneath the kitchen) is a crawlspace about 3 to 4 ft in height. To left of the basement is another crawlspace underneath the living room. It’s pretty chilly in the basement and the humidity level now is below 20%.
I have two issues I want to solve:
1) Living room and kitchen floors are cold – kitchen has 1 1/2 inch of subfloor with a vinyl finish top, living room has a 1/2 plywood subfloor with 3/4″ oak HW.
2) Reduce noise levels from force air furnace and water heater burner being transmitted into living space on first floor. Water heater is a new AO Smith sealed combustion burner unit. It actually sounds like I have a giant bunson (sp?) burner running in my family room.
Will adding insulation to the underside of the floors (ceiling in basement/crawlspace) help? I have 2×8 floor joists.
I assume I’ll have to put down a 6 mil poly sheet for a vapor barrier on the floor of the crawlspace (if one is not there right now.)
Do I used paper-faced or unfaced fiberglass batts? If I should use the paper-faced, I assume the paper should be on the basement side, correct?
Is there a better material to use (that is still economical) for insulation?
Is this a totally off the mark idea?
Replies
6-7 inches of open cell foam would do wonders for insulating against temp, air infiltration and noise. Not sure of cost in your area, but ballpark it might be .50 cents per square foot.
Crawl space insulation
Maxxman,
What is the floor of each crawl space area? and the floor of the main basement? If the crawl spaces are dirt or concrete w/no poly underneath, install the poly. If the main basement floor is concrete you can't do much else as far as a moisture barrier is concerned.
Will adding insulation to the underside of the floors (ceiling in basement/crawlspace) help?
Yes, with heating and noise.
Do I used paper-faced or unfaced fiberglass batts? If I should use the paper-faced, I assume the paper should be on the basement side, correct?
NO, the facing goes towards the warm side, but in this instance you're better-off using un-faced insulation, then installing Tyvek across the bottoms of the joists, this allows the bays to breathe properly and keeps the fiberglass from becoming airborne, this is required under some codes. Choose a High Density type fiberglass , it gives more R-value per inch of thickness than regular type batts You may be able to get as much as an R-30 or 35. or you may be able to double up on an R-15 ( 3 1/2") to get the desired effect, just remember to use the un-faced rolls.
As for spray foam, I don't think open-cell is appropriate, too much moisture in warmer weather, I would look into closed-cell instead
Geoff