installing vapor bearier under existing metal roof

mike penrod
7/12/2014
I built a lean to metal roof over a 15 X 30 patio. I have 2x6 rafters and 2x4 perlins the perlins are laid on there side. I did not install a vapor bearier @ the time I built the roof. I recently decided to close this patio in with windows & heat and cool this as living area. My plan was to install 6" craft faced insulation between the 2x6's and leave the 1 1/2" thickness of the perlins open for ventilation and install vents in the eaves on both ends and along the top and bottom edge. Will the metal roof sweat if I do this.
Eric Novotny
An informed customer is the Best Customer!
7/12/2014
Are you going to be covering the fiberglass with a drywall and paint? You would also cover the framing with a layer of rigid foam prior to the drywall and this would keep the moisture out of the assembly.
mike penrod
7/14/2014
I am planning on covering the ceiling with wood such as a wood siding or car siding do I still need to install rigid foam over the craft facing of the fiberglass insulation I figured I would overlap the craft face on the bottom edge of the 2X6's when I install the fiberglass insulation.
Eric Novotny
An informed customer is the Best Customer!
7/14/2014
The faced fiberglass should do the trick as long as the roof is vented as you say it will be.

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