Which way does insulation vapor barrier face?

Picking the right face is essential with fiberglass insulation that has a vapor barrier (meaning with Kraft paper or foil attached on one side).

  1. It should always face the warm-in-winter side.
  2. If a vapor barrier is installed on the wrong side, it can trap moisture inside wall cavities causing condensation to accumulate.

Is the paper on insulation a vapor barrier?

There are two basic types of vapor barriers used with exterior wall insulation. The most common is paper-faced insulation. The insulation is installed into the wall cavity with the paper facing into the house. This is very important — the paper, which is the vapor barrier, always faces the warm side of the house.

Does the paper side of insulation go?

Regardless of whether fiberglass insulation is installed in a wall, attic, or crawlspace; the paper facing should always face toward the inside of the home. That’s because the paper contains a layer of asphalt adhesive which prevents water vapor from passing through it.

Which way should insulation go?

The first layer should have the facing against the drywall to act as a vapor barrier. (The general rule for insulation is that the facing always goes toward the conditioned space.) The second layer of insulation should be unfaced so that moisture doesn’t collect between the layers.

Is rolled insulation better than blown?

Rolled fiberglass insulation scores an R-value of 3.7. So overall, rolled fiberglass insulation is slightly more effective at blocking in and out heat than its blown counterpart.

Does unfaced insulation need to be stapled?

INSTALLING FACED INSULATION WITHOUT USING STAPLES The insulation must fit snugly at the sides and ends. Some CertainTeed products, such as SpeedyR, are prodcuced without stapling flanges specifically to be friction fit, and do not need to be stapled.