Roxul Vapor Barrier Attic

Some debate still occurs over how necessary vapor barriers are but a consensus is growing closer.

Roxul vapor barrier attic.

In some instances the polyethylene when taped and sealed also acts as the air control layer within the assembly. With 2 layers between the joists and another layer running perpendicular over top the r value of the insulation in the side attic is in the range of r 40. The need for installing a vapor barrier depends on the climate zone of the building. Note that rock wool insulation only comes un faced meaning there s no kraft paper or foil barrier.

Roxul batts are made of mineral wool and don t support moisture like say recycled jeans shredded cotton can. Most authorities now agree that vapor barriers are important under certain conditions but not necessarily as a whole house solution for every home. Vapor barriers installed on the interior side of assemblies impede them from drying toward the interior this is a problem for air conditioned spaces and can be an issue when there is also a vapor impermeable material installed on the assembly s exterior creating a double vapor barrier wall assembly. I am doing a complete renovation of my house right now and i ve chosen to insulate with roxul comfort batts.

Resolution of the vapor barrier debate. Depending on the situation you may need to install an independent permeable membrane to serve as a vapor barrier. I chose to insulate with roxul which has a higher r value than the pink stuff. Whether you are building new or renovating your home use roxul comfortbatt thermal home insulation in your exterior walls attic ceiling and floor frames for top thermal performance.

Polyethylene is a plastic sheet that serves as a vapor barrier to resist diffusion of vapor and moisture through wall roof and floor assemblies. This is primarily due to the kerdi board or wedi. A well insulated side attic. Youll see that i mention roxul a lot in that tutorial but roxul is exactly the same as rockwool.

And by the way if you re remodeling a shower and use rockwool with kerdi board or wedi s shower system there s no need for a vapor barrier. For ceilings with sheetrock already and just a crawlspace or attic above it is our understanding from various research that there should be no vapor barrier on top of the roxul batts laid on top of the sheetrocked ceiling. I ve read that i need to use a vapor barrier but i ve also read that vapor barriers can cause houses to be moldy or can cause rot inside the walls because the walls cannot dry out properly. In circumstances where conditions inside a home or office are much different than outdoor conditions water.