flashing detail: missing something?
Just looked at a friend’s new roof in progress: it’s a panelized metal roof , pcs. about 16″x24″ +/- and look a little like shake shingles………coated with a fine, colored aggregate. ( Don’t know brand) The pieces rest on horizontal 1×2 battens, and are nailed on bottom edge’s vertical detail so that water will run past nail heads. So far, so good. 50 year warranty claimed……..My question concerns the flashing around the vents; As seen, the roof jacks are buried under particular course of panel completely. This doesn’t seem right, as I expect to see the bottom of the roof jack emerge downhill to shed water. Installer indicated that special compound will fill in the gap between . I feel like a little expansion/contraction, and this will fail, leading to water infiltrating the underside of the panels……anyone worked with this stuff?
What about neoprene boot-type jacks? or some kind of counter flashing? Appreciate some insight .