Ok folks, I've tried contacting the manufacturer of the metal roofing and am having no luck getting a clear cut answer. Hopefully someone with more experience can help me out.
I'm looking to install imperial rib exposed fastener metal roofing. I went to ABC's website and they have detailed diagrams and videos showing 'proper' installation but some of it doesn't make sense to me.
First question, seam tape. I know seam tape is used at the overlapping edges (where ribs overlap, not overlapping 2 panels end to end). I'm assuming 1/2" wide tape here? 3/8" seems too narrow. The install diagrams also show using seam tape at the closure strips both eave and ridge (inside and outside closures). Usually I've seen the foam closure strip laid down, the panels lined up over top of it and screwed down. This calls for a layer of seal tape, then the closure strip, then another layer of seal tape, then the metal panel. The closure strip already has some 'bulk' to it so it will slightly compress making a snug fit. Does using 2 layers of seal tape at both closure points sound right? If so, this will require 4 rolls of seam tape instead of 1. Which I'm fine with, just sounds to me like adding 2-3 gaskets to something which rarely works out well.
Second question, ABC offers install videos which I watched out of curiosity. In their demo, they show installing the metal roof to solid decking which I'm planning to do. They had their decking down, then roofing felt layered bottom to top like for shingles - so if moisture leaks through, it will run down a layered effect and run off the roof. Then they added the eave trim/drip edge OVER the top of the roofing felt. Sounds to me like if any moisture does reach the felt, it will run off properly until reaching the eave trim/drip edge then get hung up by the lip and may try to seep under it. Similar to covering decking with roofing felt starting at the top with the layered effect backwards trapping rather than shedding moisture. Should the eave trim with drip edge be put onto the bare decking first, then the roofing felt layered from eave to ridge to ensure proper moisture shedding? Or does it matter?
Usually everyone's advice is when in doubt, follow the manufacturer's directions. Just seems to defy common sense to me. I attempted several ABC offices to ask and clear up these questions, none were helpful including the headquarters where the sales rep they passed me off to seemed to know less about metal roofing than I do. So I'm reaching out to fellow GJ'ers. Thanks.
Included is a pic straight from their user manual showing the designation of double seam tape at closure strips. Not arguing that it's correct, rather noting it seems odd (and a bit excessive, potentially causing more problems). I included to show why I'm confused.
I'm looking to install imperial rib exposed fastener metal roofing. I went to ABC's website and they have detailed diagrams and videos showing 'proper' installation but some of it doesn't make sense to me.
First question, seam tape. I know seam tape is used at the overlapping edges (where ribs overlap, not overlapping 2 panels end to end). I'm assuming 1/2" wide tape here? 3/8" seems too narrow. The install diagrams also show using seam tape at the closure strips both eave and ridge (inside and outside closures). Usually I've seen the foam closure strip laid down, the panels lined up over top of it and screwed down. This calls for a layer of seal tape, then the closure strip, then another layer of seal tape, then the metal panel. The closure strip already has some 'bulk' to it so it will slightly compress making a snug fit. Does using 2 layers of seal tape at both closure points sound right? If so, this will require 4 rolls of seam tape instead of 1. Which I'm fine with, just sounds to me like adding 2-3 gaskets to something which rarely works out well.
Second question, ABC offers install videos which I watched out of curiosity. In their demo, they show installing the metal roof to solid decking which I'm planning to do. They had their decking down, then roofing felt layered bottom to top like for shingles - so if moisture leaks through, it will run down a layered effect and run off the roof. Then they added the eave trim/drip edge OVER the top of the roofing felt. Sounds to me like if any moisture does reach the felt, it will run off properly until reaching the eave trim/drip edge then get hung up by the lip and may try to seep under it. Similar to covering decking with roofing felt starting at the top with the layered effect backwards trapping rather than shedding moisture. Should the eave trim with drip edge be put onto the bare decking first, then the roofing felt layered from eave to ridge to ensure proper moisture shedding? Or does it matter?
Usually everyone's advice is when in doubt, follow the manufacturer's directions. Just seems to defy common sense to me. I attempted several ABC offices to ask and clear up these questions, none were helpful including the headquarters where the sales rep they passed me off to seemed to know less about metal roofing than I do. So I'm reaching out to fellow GJ'ers. Thanks.
Included is a pic straight from their user manual showing the designation of double seam tape at closure strips. Not arguing that it's correct, rather noting it seems odd (and a bit excessive, potentially causing more problems). I included to show why I'm confused.
