Inspecting here on Maui and I see a lot of woven valleys and pretty much never saw them back in Oregon. This one has me a bit confused since the roof was otherwise very nicely installed. The weave on this valley is close to a foot off the low spot. Following the path of water down the right side in the pic, it just runs right up against the lap in the shingles that come from the other side. I’m calling it out as wrong but welcome any input if you guys are familiar with woven valleys.
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It will depend on the shingle manufacturer which I don’t attempt to identify. However for example GAF requires a 1’ minimum overlap of the valley with a woven valley. That would make this a correct installation. Of course other manufacturers may have different requirements and even possibly different requirements for different model shingles.
Again I don’t try to identify the shingle manufacturer unless packaging or marked extra shingles are on site. If I question an installation I would articulate the reason and advise the buyer to have the owner or Builder provide the shingle information and install instructions to verify the installation is correct.
From what little I see yes it does appear to be a very good installation. Just out of curiosity what types of valley constructions do you normally see in Oregon and Hawaii? I ask because we seem to see it all here in North Texas.
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Back in the day we always offset the weave from the center of the valley.
Not where I am, it is always in the center of the valley.
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Back in Oregon 90%+ houses have comp roofs and of those it’s probably 80% cut valleys… the remainder metal valleys. Here in Maui it’s virtually all woven valleys but there are far less shingle roofs. Tile is common on nicer houses. Corrugated metal panels are also very popular. I’m not a huge fan of those metal panel roofs since the fasteners are all exposed and leak.
As for the valley I’m asking about I just don’t see how it’s correct to have the water run down the roof (right slope in the pic) at the overlap/tar strip that seals the shingles that extend from the left slope up past the low-point in the valley. Isn’t that just destined to lead to water migration under the shingles at some point? Here’s the pic with a circle of the main area that got my attention:
Unfortunately that’s how it will be with the roof design shown. If they properly overlap the shingles and provide proper flashing/underlayment at the valley then the manufacturer may not consider it an issue. Most if not all manufacturer’s install literature I have viewed tend to handle the weave process in their instructions. Again that would be why it is important to know whose shingles they are.
I see and understand your concern but would not myself be adverse to this weave if again it is 12" or more up the other side of the valley with proper flashing/underlayment. This condition is somewhat akin to a California Valley (with the concept of water striking the tab end) and many manufacturers approve of the Cali Valley, at least in our drier/low snow/low ice areas.
Just curious on the valley construction in different areas is why I am asking.
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Yeah, the regional differences in construction between Oregon and Hawaii are pretty interesting. I’ve honestly done a lot of learning “on the fly” here.
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