Moisture between underlayment, plywood, and metal roof
We’re building a sunroom addition, nuts to do this in winter, especially this winter in the Atlanta area, but so it is. I’m doing a lot of the work myself, help from a metal roofer with other skills. This contractor wasn’t finished framing a 1.5/12 shed roof dying into a 5/12 roof, waiting to sort out a particular issue, but went on to place 1/2 plywood, Rhino underlayment, then 24 gauge 1.5″ standing mechanical seam metal roof panels. The underlayment running out the top runs a couple feet, was tucked under asphalt shingles from garage roof, a couple screws thrown in to keep it down. It wasn’t enough, underlayment blew loose, it rained, moisture showed up in several places, inside adjoining garage, pools also formed in addition. The contractor disappeared for various (lame) reasons and then the legitimate reason of this wintry mix that’s put a big comma in life around here as of recent.
I tucked the underlayment back under the shingles, secured it adequately, a subsequent rain shows we’ve stopped water from flowing into either structure, garage and addition. My concern is what all this portends for moisture that I have to assume might be between metal panels and underlayment, underlayment and plywood, as well as in and through whatever layers belonging to the garage roof that are under the new shed roof. I’m disinclined to cover anything up, restricting airflow in any way to layers of materials with moisture sitting in between. How big an issue is this? Must I have the panels removed, underlayment removed, let it all dry before reinstalling? Or, will a couple days in the sun be enough to cook the moisture free? I appreciate your time.
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