It depends upon the style of valley you're using but oftentimes with the profile of panel you're installing, a butyl tape or sealant would be used. As you know, adhering to manufacturer requirements is critical so I would suggest going back to the roofing manufacturer for this level of installation detail.
Thanks so much.
Todd Miller
2013-10-07 05:37:31.000000
I am installing an "ABM" corregated metal roof which has overlapping joints (not an interlocking standing seam system) on a new 9/12 roof for a kitchen addition. In addition to ice dam and formed metal flashing under the panels, do you recommend any other type of sealant where the main roof and dormers meet in a valley? The roof has a 20' run (peak to gutters) and is 45' long, I am concerned about ice forming in these valleys in the winter and working it's was up under the corrugations. Earlier in life I did a considerable amount of construction, to include roofing, but this is my first metal roof installation. I try not to use sealants where possible when roofing, but thought there may be standard preformed accessories or recommended sealants in the metal roofing industry to address this. Thank you.