I had a neighbor once that blew insulation into wall cavities. You may not have this issue in a 1941 house (is it drywall or shiplap inside?)--but one problem he had is that if you blow too much insulation in it can push the drywall right off the studs!

I'd think it would be a far better alternative than taking off siding, though! It just leaves a small hole, between each stud space, to patch.

Regards,

-k2 in CO

Moderator, Miscellaneous Forum

http://www.bobvila.com/BBS/Miscellaneous

if the walls have some type of insulation in them already then blown in may not fill all the space.the insulator usually drills holes and then uses a wire to check for structure in the way that would prevent the blown in from getting to places in the wall.

and the insulator will just pop out a shingle for each hole making the holes easy to cover up.