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)
Air-Sealing Between Chimney & Framing
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
Vented Vs. Unvented Crawlspaces
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
Preventing Mold On Bedroom Walls & Ceilings
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
How to Prevent Condensation in Cathedral Ceiling?
Q: I’m currently dealing with insulating a cathedral ceiling, which has become a major issue. I’ve been researching solutions but feel stuck in figuring out what’s the best way to go about dealing with the problem. I have a shed roof with 2:12 pitch, built with 2x8 roof joists. It’s a mobile home that’s 14x76, so the roof is just one continuous slope. I live in northern … [Read more...] about How to Prevent Condensation in Cathedral Ceiling?
Insulating A Cathedral Ceiling With Foam Board
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
How To Protect Foam Insulation on Foundation?
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?
Do Heat Pumps Work In Cold Climates?
Q: Do heat pumps work in cold weather? I have a leaky farmhouse in Vermont with an old oil furnace. One contractor recommended adding a couple of mini-split heat pumps in the main living spaces and to use the oil furnace as a backup when it’s below zero. How much can I expect to save on my heating bills? — Gary M. A: Until recently, heat pumps were mainly used in mild … [Read more...] about Do Heat Pumps Work In Cold Climates?