Home>Discussions>INSULATION & HVAC>Insulating old wall
2 posts / 0 new
Last post
Insulating old wall


I'm looking for some advices on how to go about insulating an old wall exterior wall. The house date 1930 and behind the plaster we only have a 1inch air gap made of 1 inch rough strapping and then black paper (then its wood planks and bricks). The nort side wall I can reframe a 2x4 wall and insulate normally with fiberglass but the east side I have a window and a door so adding 5 inch to the wall is not an option. Spray foam is not an option (doing this myself) and I heard bad stories about DYI using 2 component spray foam so I was wondering if using 1 inch rigid foam then adding strapping over it for air space and drywall could be an ok option.

Edit: This is in Montreal so cold climate ;)



Re: Insulating old wall

Hi, Guillaume -


There is a spray foam company near Chicago, Illinois USA called Foam It Green. They have videos for retrofitting spray foam into existing wall cavities by removing your baseboard, making a small diameter hole in the drywall/plaster, and then spraying foam into the wall cavity with a tube. It seems to work pretty well.

Sponsored Stories

TV Listings

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