adding vapor barrier to existing metal roof

Clay Zimmerman
11/8/2013
I have an existing wood frame metal building that was built without bubble wrap or any kind of vapor barrier under the roof metal. I now wish to put in a ceiling and blow in cellulose insulation. But what about condensation on the roof? I did not want to tear off the tin to put on bubble wrap and then reinstall it but one builder said the barrier needs to be right next to the tin. I was hoping I could tack up the barrier to the bottom side of the 2x4 nailers. this would give me a 1 1/2" air space. Can someone enlighten me? Yes, I know I do need to vent the attic space.
Todd Miller
Classic Products, Inc.
11/9/2013
A vapor barrier is a good idea and I do not see any problems with your planned placement of it.
Info @windowsonwashington.net
An informed customer is our best customer.
11/11/2013
Against the nailers or directly behind the drywall is fine.

If you would like to reply to this thread, please log in. If you do not have an Ask the Experts forum user account, create one here.

Find a Contractor

Get Started Today

Take the first step to increasing the value of your home with a great looking, durable, fire resistant and energy efficient metal roof. Browse our list of qualified MRA Member Roofing Contractors in your area for a free consultation and estimate.