Hello. Am I getting this right? There's no real solution to insulating closed wall cavities? Any form of slow rise foam, apart from being economically prohibitive when filling the entire cavity, will blow out the plaster. And blown in cellulose will saturate because of no way to get a real vapor barrier on the inside (cold winter climate). So is there a way to wisely insulate without gutting interior walls or stripping exterior siding/sheathing? Thanks
I've had cellulose in walls without a vapor retarder for 25 years in central Pennsylvania. About a year ago, I opened up a large wall area for an addition and inspected the wall cavities and wooden sheathing. I could find not evidence of damage or any ill effects from the cellulose. It hadn't settled either, which tends to be a claim at times. If you are really concerned about moisture infiltration, you can paint the interior walls with a low permiability coating. This effectively becomes a vapor retarder and in the best possible place as well. It can then be painted with a finish coat if desired. That would provide you with a cost effective solution and a very good insulation system.
Posts: 216 | Location: Annville, PA | Registered: 03 July 2006
Actually there is a product out now that is made specifically for retrofitting foam into existing walls. The product is called retrofoam. It comes out of the hose about the consistancy of shaving cream and does not expand inside the wall, so will not blow out as traditional foams will. Not cheap and not for the DIY'r but does have the higher R-value of foam insulations. Might be worth a look for you.
