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hausdok

Master Roof Idiot Final Roof Valley Exam

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Every time I see one of these I just shake my head and ask myself why it is they don't have mandatory training and education for framing and roofing guys.

Yesterday's roof.

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It was raining like hell when I started, so I did the interior, electro-mechanical, attic and crawlspace first. Here's what I found in the attic of the left garage (left edge of the garage roof at the extreme left in the photo.)

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Closeup - If the OSB is this black where there is ventilation, it's a safe bet the inside of the garage/living room wall is going to be nasty.

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The wall is just a tad damp.

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Leaking through into the crawlspace under the corner of the living room.

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I'm thinking that the only way to make this work is either completely lining this with IWS or a custom-made metal flashing that conforms to this outline.

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What say you, Boys?

ONE TEAM - ONE FIGHT!!!

Mike

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I think the mouth of that valley needs to be wider, or it will jam up with debris. The framing crew screwed up because the design is f%&ed. The roofers just started banging down shingles cuz that's all they ever do.

Back to the drawing board, eh? The architect could design a cure, but why pay him more money? The triangular piece should slope down from the wall to direct the water out and away. A trough like what you drew, but with slope on both sides. Up here, it would be roofed with torched on mod bit, maybe with an open metal valley so it will flush the leaves and needles out.

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That looks like a really stupid addition. It can't be original, can it?

You can make that detail shed water just fine by lining the whole area with IWS. The better solution is to install a new cricket. This time, instead of letting the tip of the triangle come to a point, end it with an 8" wide blunt tip. That will make the cricket a bit more shallow, but it doesn't really matter because you're going to line it all with IWS anyway. Then you'd have an 8" opening instead of a pinpoint opening that a tennis ball could clog up.

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Yeah Jim,

I agree. It actually did clog up with a one-inch thick chunk of moss and a bunch of roof granules. The owner says they'd had the roof pressure-washed several times over the years. It's all original.

ONE TEAM - ONE FIGHT!!!

Mike

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Every time I see one of these I just shake my head and ask myself why it is they don't have mandatory training and education for framing and roofing guys.

I think the problem begins with the design. Architects that seem to have cross-gableitus don't ever show a detail to get water out of valleys. The contractors just make it like the picture. Add Fall leaves, some ice and melting snow and it's a rotting mess in just a couple years.

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Every time I see one of these I just shake my head and ask myself why it is they don't have mandatory training and education for framing and roofing guys.

I think the problem begins with the design. Architects that seem to have cross-gableitus don't ever show a detail to get water out of valleys. The contractors just make it like the picture. Add Fall leaves, some ice and melting snow and it's a rotting mess in just a couple years.

I agree. No half measures. Without a drawing of the overall roof framing all I can suggest is that the roof plane on the right side of the valley be elevated to shift the valley away from the wall so that it will terminate at an eaves.

Marc

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You guys still have architects designing houses? Around here their all home designers, meaning someone that likes to draw pictures of houses on their computers. The so called plans that become houses are certified by an engineer, usually a civil engineer that knows nothing about houses. I've seen stamped plans that were drawn in two different scales on the same drawing, plans missing elevations, and the funniest (saddest?) a girder that was specified to be three different sizes-12", 14" and 9" LVLs as the loads changed. How exactly does one switch from a 14" beam to a 9" beam over a single column?

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How exactly does one switch from a 14" beam to a 9" beam over a single column?

Every carefully. [:-bonc01]

ONE TEAM - ONE FIGHT!!!

Mike

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One of the best books on this topic (now out of print) is "Problems in Roofing Design" by Harrison McCampbell.

Very few architects understand design in terms of water resistant performance; they're not trained to think that way.

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Every time I see one of these I just shake my head and ask myself why it is they don't have mandatory training and education for framing and roofing guys.

I think the problem begins with the design. Architects that seem to have cross-gableitus don't ever show a detail to get water out of valleys. The contractors just make it like the picture. Add Fall leaves, some ice and melting snow and it's a rotting mess in just a couple years.

Couldn't agree more and I see it all the time.

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your outline looks like a pyramid to me w/two sides trapping water against the house & roof. Make a rectangular cricket sloping down from both walls back to the roofline. I agree it should be as wide as possible where it spills off the roof. You're probably limited by the bottom edge of the window but it should be enough height. This space will always need to be checked for debris buildup.

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Haudok, what about snow in your area? I'd recommend IWS higher up from before that window also to prevent water infiltrating the window framing from all the snow that would sure to be built up in that area.

Well the amount of snow that'd be built up from where I'm from... ;)

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Snow?

Nah, not likely. We got about 10 inches in a storm in January of 1997 but nothing significant since. Ironic that. Less than an hour's drive they had 16ft. of snow through the winter and a week ago a car was pushed across Rt. 2 with all its occupants in it by an avalance.

One of the weird percs of living in the western corridor on Puget Sound, I guess.

Taking it up those walls about 12 to 15 inches above the bottom would probably do fine. If it were custom made, it would have to have a flange that wraps around that vertical corner behind the trim as well as wraps down over the fascia behind the gutter and on that rake. That friggin piece of vertical trim is about 1/4-inch above the surface of the roof and almost completely fills that tiny little notch.

The site super on this job must have been more than mildly retarded.

ONE TEAM - ONE FIGHT!!!

Mike

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