Home>Discussions>INSULATION & HVAC>Adding insulation in existing finished walls?
6 posts / 0 new
Last post
Adding insulation in existing finished walls?

Hello, all. My house was built in 1985 and I'm sure that the R-value isn't up to modern codes and standards. Is there a way to increase insulation/R-value without stripping down to the beams and starting over?

MLB Construction
Re: Adding insulation in existing finished walls?

if your house was built in 1985 it should have fiberglass batt insulation in the exterior walls, R-13, which is considered up to code. this will prevent you from adding blown-in insulation from the interior or exterior. the only possible solution that i can come up with is to cut a channel, approximately 2' high (equidistant from the floor and ceiling) through the middle of the interior side of the exterior walls. this way you can reach in and remove the insulation from your opening up to the ceiling and from your opening down to the floor. after that, you can patch it up and have blown-in insulation installed or put in new fiberglass batts then patch it up.

Re: Adding insulation in existing finished walls?

Hi, Adding insulation to the walls will not solve the problem. If you want to make the house warmer and lower your heat bill, I would add insulation to the attic and floors. Thanks

Re: Adding insulation in existing finished walls?

There are more efficient insulation types now than they had then, but you'd never reach a pay-back point trying to change them out. Where the codes and recommendations have changed most is in the attic area- check and see what's up there and if needed, blow in more. Floors may also need an upgrade, that will vary based on where you are. Here in the south back in '85 nobody did the floors- now it's code. There's a lot to be gained by caulking and sealing, especially wall openings at the plates- again back in '85 here, firecaulking wasn't required but is now which seals these leaks. And darn near every window was never caulked under the trim that supports the stool inside even though the rest was! Ditto for the top of door casings where they meet the wall. Look for things like that and seal them up. To complete things, insulate the rim joist and that should be about as good as you can get without spending more than you'd save.


Re: Adding insulation in existing finished walls?

Good info. Thanks to all!

Re: Adding insulation in existing finished walls?

Check with your local power supplier. Some have a free "energy audit" where they come to your house and check out attic insulation, windows, etc. They might even have coupons for insulation services, etc.

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.