Most authorities now agree that vapor barriers are important under certain conditions but not necessarily as a whole house solution for every home.
Vapor barrier roof rafters.
Attic vapor barrier detail for cold climates the best approach for a vented attic in a cold climate is installing a layer of drywall with a good coat of latex paint the paint creates a semi permeable vapor barrier.
The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below.
Hopefully you have installed a vapor barrier between the roof purlins and the roof steel.
A roof design that includes an adhered roof membrane with multiple layers of insulation with board joints offset and staggered over a vapor retarder air barrier helps lower the risk that air and the moisture it carries will infiltrate the roof system.
The previous owner has 1 foam insulation with a a plastic vapor barrier only on the rafters of the roof about4 from the slate roof but not on the walls of the attic.
I have a 1961 single story home with a cement floor crawl space.
Whether or not you use vapor retarder you want an air tight air barrier such as well sealed drywall to keep out moisture from the house.
To know if you need a vapor retarder ask yourself a few basic questions.
Not flammable but it must be protected with wallboard.
Plan is to after foam put barrier and steel panel up and then.
White bubble between roof and rafters.
Not recommended for exterior below grade applications.
Vapor barrier on under side of floor joists over a crawl space oct 26 2011 alex in seattle said.
We have some moisture issues that i will address at a later time but i d like to install a vapor barrier on the underside of the 1st floor subfloor as well as insulation.
Whether or not you need a vapor retarder hinges on three main factors your climate your home and the location of the wall you re insulating.
In circumstances where conditions inside a home or office are much different than outdoor conditions water.
My question is should iuse a vapor barrier inthe attic floor.
You could insulate the roof the traditional way.
No wrap on walls.
A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.
Rosemary june 5 2015 at 3 03 pm.
Some debate still occurs over how necessary vapor barriers are but a consensus is growing closer.
Resolution of the vapor barrier debate.
Its closed cell structure stops water vapor and the foil covered face acts as a radiant barrier.
From what i ve read online it seems wise to install a vapor barrier over the plywood to prevent condensation from getting absorbed into the plywood from the steel roof.
There are certainly other options.
4 times the cost of fiberglass batts.
But it seems the.
