The building envelope includes the exterior walls, roof, windows, doors and the foundation and/or ground floor. As elements of the building envelope, vapor barriers and house wraps are a critical ...

what should I use as a vapor barrier? Also, your advice on three other questions would be helpful: 1. Should I caulk where the siding meets the windows? 2. When I nail the siding, should I avoid ...

Q In your recent answer to a query about loft insulation and condensation (January 18), you said an impermeable vapour barrier should be installed. Can you explain what this is – what type of ...

L. Lee, email ANSWER: Condensation is a common problem with walls inside crawl spaces insulated using conventional fibreglass batts and polyethylene air vapour barriers. It is very difficult to ...