Bruce Harley

Get insight into the complicated relationship between ridge vents, gable vents, and attic floors.

Q: I keep hearing talk touting spray-foam insulation as a “superior” insulation material. I’ve been building for nearly 20 years, however, and I’ve occasionally found spray foam that has settled…

Q: In Bruce Harley’s article “Home Remedies for Energy Nosebleeds” (FHB #190), there’s a picture of a can of spray foam labeled Fireblock Foam next to a caption about sealing…

With a little detective work, you can correct construction mistakes and cut energy bills by a third or more.

Q: Maine summers are wonderful, but the upstairs of my Cape-style house is hot and stuffy. I run both bathroom fans (100 cfm) during the night to cool the house, but…

Q: It seems to me that it would be a lot easier to install rigid-foam insulation inside the framing rather than outside because of all the details such as cornice returns…

Building-science expert Bruce Harley explains the wide swing of moisture content in a home's air from summer to winter, and he offers some tips for controlling it.

Q: I’m building a house with 2x4 studs, sprayfoam insulation in the stud cavities, and blown-in cellulose insulation over a plastic vapor barrier in the attic. Ross E. Iverson, Sheridan, WY…

Q: What ventilation concerns do we face if we dense-pack cellulose into the rafter cavities between the ceiling and the roof? Bob Tidball, via email, None A: Bruce Harley, an engineer…

U-factor and R-value measure heat transfer and heat resistance, respectively; understanding the difference will help you select energy-efficient windows and insulation.