Vapor Barrier Attic Floor

You can forego the plastic and use a vapor retarder kraft faced insulation or latex ceiling paint in all other climates except hot humid or hot dry climates.

Vapor barrier attic floor.

Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. Because it s nearly impossible to seal penetrations in the ceiling the reality is water vapor will get into the attic. Most forms of attic insulation benefit from the addition of a vapor barrier to protect them from the harmful effects of moisture which can reduce their effectiveness over time. If your climate does not meet these conditions a vapor retarder like latex ceiling paint will work well for your house if you are in all other climates except the hot dry and hot humid.

The following are a few simple steps to help you undertake the task properly so your vapor barrier retains heat without damaging the insulation. Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case. Attic vapor barrier detail for cold climates. A plastic vapor barrier is best installed in a vented attic within climates with over 8 000 heating degree days.

Even though we apply vapor barriers to exterior insulated walls in cold climates it s no longer recommended for ceilings floor of the attic. Crawl spaces benefit from a polyethylene moisture barrier placed directly over the exposed earth. A vapor barrier against the concrete surface is generally recommended before wood framing or flooring materials are installed.