I live in a semi-detached home and I was wondering if you could advise how to insulate the common wall in the basement? Does the common wall require a vapour barrier?
Answer:
I've found that common walls that are insulated also profit from being sound proofed so you have your work cut out for you. When insulating any below-grade masonry wall it is best to build (in place) a 2X4 structure with studs 16" O.C. and pull it an inch and a half from the wall in order to accommodate R-20 fibre insulation bats without compressing them. The insulation actually goes from the sub-flooring above to the concrete floor.
Sound proofing a wall or ceiling, I’ve found, is best done by creating a sandwich with lots of bulk. I apply 5/8” gypsum board (roughly taped, jointed and sanded) to the studs or joists and then 7/8” sound absorbing fibrous panel manufactured for the purpose. On top of that, I apply resilient channel (16” O.C.) and then another layer of 5/8” gypsum board. This time the gypsum board is properly taped jointed and sanded.
Courtesy of Ren Molnar, Construction Consultant at HomeFocus.com. I can also be reached at (613) 748-3003 and Home Focus phone-in is broadcast live 8 to 10 A.M. (Ottawa, Ont. time) on Saturdays on www.cfra.com.
