Insulate or Install a Vapor Barrier

Tips from Real-Estate-Agents.com

by Kathy Maynard, reprinted courtesy of ServiceMagic.com

Q: I am removing lathe and plaster interior walls from the second floor bathroom of my two-story home (built in 1900). The siding is asbestos shingle over 12 inch wood lap siding. All of the walls that lead to the exterior have rock-wool insulation blown into them.

I intend to sheet-rock my bathroom and insulate the walls that lead to the exterior with fiberglass insulation. I want to know if I should first put up any vapor barrier. Once the rock-wool is removed it exposes the back side of the 12-inch wood lap siding, nothing else. In other words, the interior wall leads directly to the siding with nothing but the rock-wool as a barrier. Should I put up Tyvek or Visqueen between the studs? Or since it ain't broke should I not fix it and just re-insulate with Fiberglas and leave as-is?

A: I contacted an insulation contractor for the following advice:

The problem with vapor barriers is that if you don't do it just right you can end up trapping vapor in an area you don't want it especially in a kitchen or a bathroom.

I would just use unfaced-friction-fit fiberglass batts as they would give you R-value and help with noise, as well as, fit tighter. In a new home that is what they would usually use. I recommend using the new green sheetrock with an R-value if you can afford it. Considering the energy savings, the moisture resistance and the noise control, I think it is really worth the extra investment.

To locate a reputable insulation or any other kind of home improvement specialist, please return to our site at: http:/www.servicemagic.com, and let us match you with the ideal service professional in your area.

Good luck!

Kathy Maynard

-- Tips courtesy of Service Magic