Woven vs. Closed Cut Valleys

Originally Posted By: Bill Deatrick
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I was recently asked if a woven valley roof was better than a closed cut valley, and frankly I didn’t have an answer. Does anyone have an opinion on this one way or the other?

I have heard that a woven valley was more difficult to install and that if it wasn’t done properly could be a problem, but it would seem to me that the closed cut (if done correctly) would be tougher to install.


Originally Posted By: Guest
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Closed cut valleys are attractive but depend on the traditional method of valley installation including flashing, ice water dam and roll roofing. The other thing about closed cut valleys is the top of each shingle must be cut back at a 45degree angle where it intersects w/ the valley or water coming down the valley will hit the shingle top and migrate across where it either soaks the sheathing or actually leaks into the structure.

Woven valleys aren't too difficult to install, don't require the flashing step in preparation (I still use flashing anyway) and are very long lasting.
The only problem with woven valleys is they look kind of lumpy.

Originally Posted By: James D Mosier
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30 ~ 40% of the woven valleys in my neighborhood leak. All houses less than 7 yrs old, most leaked right away, only on the single story houses. These were not built by people that had a clue or even cared for that matter.

I watched them do a couple and really couldn't see how you could screw it up but apparently it's not too hard to do (screw up).

Three tab shingles aren't that thick these days but I wouldn't do it with dimensional shingles.

Jim Mosier