Q: I have an unfinished space above our garage that we are converting into a flex space. It has a cathedral ceiling. We are in Houston, TX so I am concerned about the heat and humidity in the space. The west side of the space is sloping roof with soffit and gable vents along the entire length, so creating a baffle out of rigid foam is simple. We have knee walls with … [Read more...] about Best Approach to Hot-Climate Cathedral Ceiling
Energy Conservation
Frost-Protected Shallow Foundations
Q: We are building a family home in Toronto, Canada using a local builder. Due to soil conditions, we had to raise our founding level. The code requires the underside of footings to be 4 ft. below grade for frost protection. In our case with a sloping grade, the footing depth is 4 inches less than the required 4 ft in some locations. The structural engineer’s opinion is … [Read more...] about Frost-Protected Shallow Foundations
Can I Foam Basement Wall With Existing Studs?
Q: We are looking to refinish our basement in Portland OR. Because 2x4 wood studs are already installed, we can’t install foam board tight to the poured concrete foundation. Can closed cell spray foam provide effective barrier and insulation instead? Or will thinner spots behind studs limit effectiveness? - James A: It sounds like you have some space between the studs … [Read more...] about Can I Foam Basement Wall With Existing Studs?
Combining Foam & Fiber Insulation in Cathedral Ceiling (Flash & Batt)
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?