Avoidance of the installation of vapor barriers such as polyethylene vapor barriers foil faced batt insulation and reflective radiant barrier foil insulation on the interior of air conditioned assemblies a practice that has been linked with moldy buildings lstiburek 2002.
Vapor barrier over rigid foam insulation.
It will degrade its r value.
When installing the foam use caulk or tape for maximum insulation between the material and the board or floor.
Most authorities now agree that vapor barriers are important under certain conditions but not necessarily as a whole house solution for every home.
After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.
To complete the vapor barrier you would want to foam seal or tape all the sides where the rigid meets timber because these gaps will facilitate vapor flow.
This barrier is meant to keep moisture from getting to the insulation in the walls and ceilings and it is required by building codes when insulating most houses.
A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.
Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets.
In any case the vapor barrier must point to the warm side.
Some debate still occurs over how necessary vapor barriers are but a consensus is growing closer.
All foam boards absorb water vapor.
Keep foam board insulation away from direct sunlight prior to installation.
In circumstances where conditions inside a home or office are much different than outdoor conditions water.
Cover the insulation with a vapor barrier before you install it.
Not every wall does.
It goes without saying that the holes would not be a good thing.
Resolution of the vapor barrier debate.
However an installation between the studs can pose a challenge.
By installing the crawl space vapor barrier over the insulation you will prevent holes in the vapor barrier from securing the rigid foam to the wall.
However please be aware that spray foam is not the same as rigid foam.
However an installation between the studs can pose a challenge.
Rigid foam insulation is usually a qualified vapor barrier.