Q&A: A Forum for Green Building Experts and Beginners

Our home has a crawl space under the living space of the home as well as a partial basement to one side. We had a plastic vapor barrier over the clay floor of the crawl space.

A contractor who did some work on the home advised that this was incorrect, removed the plastic vapor barrier from the clay floor of the crawl space and instead installed insulation along the top of the crawl space (beneath the floor of the home) with a vapor barrier covering this.

A client asked me about them on a big reno we're doing. I always assumed they were largely hokum (sp?). Can't find much research on the web on the subject. Seems to be "can't hurt."

THe house is just outside Portland ME. Plenty of trees around, tallest structure for several hundred feet, but it's also hilly, reasonably high housing density, not in a field in the middle of nothing else above shrub height. Is it worth the effort to install a system? Anyone actually seen any research?

Hi all, great site here, I've found lots of helpful information already.

I recently bought a 35 year old house in a Zone 6 area and it needs a new roof. This seems like the best time to do the attic insulation, but with all the expenses of our first home we're running low on cash. We've budgeted around $5K for the whole project this summer and plan to do as much as possible ourselves. I've read through many articles here and on buildingscience.com but I'm kind of stuck.

We didn't produce this video -- it was actually produced by Builder magazine -- but it features two people known to GBAGreenBuildingAdvisor.com readers, Dan Morrison and Peter Yost.

Dan and Peter visit a construction site in Arizona, and inspect air barrierBuilding assembly components that work as a system to restrict air flow through the building envelope. Air barriers may or may not act as a vapor barrier. The air barrier can be on the exterior, the interior of the assembly, or both. details and water management details.