Valley Flashing Options?
Jim Orasky| Posted inGeneral Questionson
Per my roof installer, the roofing shingle I have specified (Certainteed Presidential) cannot be woven in the valleys. He says it voids the warranty. He says we have to go with metal flashing (over the usual Ice and water barrier). Is there any other product I should be looking at besides the aluminum (.032) or copper (unknown gauge) he offers? Pitches are 6 1/2 and 8. The reason I specified this shingle was the “heavy texture” appearance so I assume any similar shingle will have the same restriction.
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Replies
Jim, check out the right side of the first page:http://www.certainteed.com/resources/PresidentialShakeTLInstall.pdf. Woven valleys never work with laminated shingles (or with unequal pitches) but closed cut valleys usually work fine. Because this is an extra-thick shingle, an open valley is the best idea, but it does not appear to be a manufacturer's warranty issue. I don't know of any metals for valleys other than aluminum, copper or steel, all of which are available with various coatings.
Jim,
Whatever type of flashing metal you use, be sure that your roofer makes the exposed flashing wider at the bottom than the top. (In other words, don't cut the shingles parallel to the valley). That way, ice will clear faster.