Rockwool Vapor Barrier Attic

If it becomes damp or wet the insulation when dried out will maintain the original performance characteristics.

Rockwool vapor barrier attic.

Furthermore stone wool insulation does t wick water. Rockwool insulation is moisture resistant yet vapor permeable. A natural inert plaster stucco on that. Drywall with taped seams.

Any water that contacts the outer surface will drain and not be absorbed into the body of the insulation. Despite the fact these two barrier systems are neither the same nor interchangeable there is sometimes confusion in the industry as a single material is often used for both functions. Rockwool stone wool insulation does not wick water which means that any bulk water that contacts the outer surface will drain and not be absorbed into the body of the insulation. I design my envelop with two materials that mate well mw and 100 wood period.

While there is no need for a vapor barrier you certainly need an air barrier in this location. I d personally seal the attic and not use any petro based papers or non inert vapor retarders barrier materials or house wraps like most foams wraps that don t work since they lack cfm or high perm nor are chemically stable. Fiberglass insulation for a 2 6 wall costs between 57 cents and 72 cents per square foot. Interior moisture that cannot be eliminated must be controlled by employing an effective air barrier and vapor retarder barrier.

That s a significant difference especially if you re insulating an entire house or large addition. The best air barrier material in this case would be 1 2 in. Rockwool insulation is moisture resistant yet vapor permeable.