Q: I had some moisture in my basement this winter--got onto the carpet foam and made a mess. I removed some drywall to see if there was a leak, but the only obvious issue is wetness on the vapor barrier directly behind the drywall and dampness in the drywall as well (see photo). Any ideas how to deal with this? The foundation and fiberglass insulation appear to be … [Read more...] about How To Diagnose Leakage In Finished Basement?
Q: I am renovating and old home with an uninsulated, non-vented walk up attic built in 1848. The shingle roof is less than 10 years old. The simple gable roof has 2x6 rafters. I’d like to apply 2 in. of closed-cell foam and then install 3 ½ in. of R-15 rockwool and add an Intello “smart” vapor retarder. The finished ceiling will be1/2” nickel gap shiplap. Will this approach … [Read more...] about Combining Foam & Fiber Insulation in Cathedral Ceiling (Flash & Batt)
Q: What’s the best way to air seal and insulate between a masonry fireplace and the surrounding wall? There is a lot of contradictory advise around about how to handle this. I will be installing a direct-vent gas insert with aluminum liners in my fireplace opening, so heat in the flue cavity will not be a big concern. The chimney material is cement block above the … [Read more...] about Air-Sealing Between Chimney & Framing
Q: What are the best practices for a vented crawlspace? I bought a townhome last Nov. that has a vented crawlspace with a sump pump. There is a vapor barrier on the ground. There is a truss floor system that has faced batts that hang below the subfloor (the facing does not touch the subfloor), the rim joist was sealed with spray foam at the top and bottom and filled with … [Read more...] about Vented Vs. Unvented Crawlspaces
Q: I have a damp spot in the corner of the bedroom. It is and outside wall corner. It is a bungalow so no bathroom over it. The damp spot seems to dry at times but there are tiny mold spots on it. Could it be that there is not enough circulation in the room? The window in the room becomes full of condensation when blind is down in winter so thought that may be part of … [Read more...] about Preventing Mold On Bedroom Walls & Ceilings
Q: What is the best way to insulate an unvented cathedral ceiling in a detached workshop? I plan to insulate before installing an AC and heating system (thinking mini-split). Is closed-cell spray foam the best, or only, good option in this case? I don't plan on finishing the space with drywall, although wouldn't rule it out in the future. .And given that it's only a workshop … [Read more...] about Insulating A Cathedral Ceiling With Foam Board
Q: The foundation on my 1980s-era house is insulated on the exterior with sheets of foam board. Several inches of foundation are exposed above grade, where the foam is protected by aluminum flashing. The foam and flashing are unsightly. Would it risk termites or other problems to raise up the ground level with soil or river rock to cover up the foam? Are there better … [Read more...] about How To Protect Foam Insulation on Foundation?
Q: I'm tearing the house down to bear studs inside and outside. I'm putting 1-inch rigid foam board on the outside. Do you suggest foil-faced or unfaced foam board? Where and how should I use moisture barriers in the construction of the interior walls? I live in zone 5, should I use rain screen? What do you think of cement lap board for siding? – Ron B. A: Foam … [Read more...] about How To Install Foam Sheathing: Thickness, Vapor Barrier & Housewrap?