On 2/20/2011 9:16 AM, cj wrote:
i would like to beef up the insulation on our sunroom ceiling and i
thought that a layer of rigid foam board with some half inch plywood and
shingles on top off that would do the trick as well as somewhat
soundproofing the room from rainstorms that can be deafening. the
ceiling(interior and exterior) is a thin gauge aluminum and i am not
sure how to attach the foam board/plywood to it. what type of fastener
would work best or combination of fastener and adhesive...i am thinking
of a fine thread type of sheetmetal screw might work.
thanks, cj

Based on sunrooms and metal porch roofs I have seen, with undersized C
or H channel rafters and purlins on 24" or 36" centers, I suspect what
you propose would likely exceed the load capacity of the existing roof
structure. (Especially if it snows where you are, and you get a heavy
snowfall.) The foam is light, but plywood and shingles add up fast. Plus
of course your weight as you are installing it. You could fit foamboard
panels to the inside, and cover them with those plastic-coated faux
beadboard sheets, or maybe plastic soffit panels, if you can find stock
long enough. That wouldn't weigh much. The dead space might create
condensation issues, though, so you would have to find some way to keep
air flowing through there, with screens to keep mice and bugs from
moving in.

No disrespect, but you seem to be over your head, and we can't see your
sunroom from here. Suggest getting local sunroom and awning dealers to
stop by and discuss possible options. They may even have
insulation/dress-up panels in their catalog.

I'd LOVE to have a tin-roof porch or sunroom, for summer thunderstorms.
I find the sound soothing.

--
aem sends...