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.
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.
4/10/2017
Isaiah Industries, Inc.
4/10/2017
4/11/2017
We currently have a contractor who is supposed to be installing metal roofing on our two low-slope (2:12 and 3:12) dormers (asphalt shingle on the rest), but now that we are at the installation phase he is pushing for modbit, or even just asphalt shingle over the whole thing.
Is he correct that we shouldn't go with a standing seam hidden fastener system, but instead modbit or EPDM? He even said he would recommend asphalt shingle over metal for us.
He has two reasons for suggesting modbit or EPDM:
Even with replacement of rotten wood in the original sheathing and new OSB there is some cupping to one of the dormers in particular that he thinks will lead to installation issues between panels with the standing seam.
He isn't sure how to handle the ridge vent where the metal roof and asphalt shingle meet. We have a 1 1/2 venting space between some added exterior rigid and new OSB that now forms our sheathing.
9/16/2020
Thanks. Proper installation is critical with all metal roofs. It sounds like your contractor is not overly experienced with metal? There are plenty of metal products that could be used on your roof pitches, especially for short rafter lengths that do not care much water. I'd think a 1.5" or taller snap lock would work fine. I believe that all asphalt shingles require a 3:12 pitch. Perhaps your contractor could work with an experienced metal roofing contractor / installer to accomplish what you need?
Isaiah Industries, Inc.
9/17/2020