# Open or closed valley



## kmegk9unit (Apr 21, 2014)

I'll be be roofing my house soon and thought I ask what everyones opinion on a closed or open valley. I like the way the open valley looks but is it better than a closed and how will it hold up? Some say its a little more work. I also was thinking about using copper in the valley instead of aluminum over the ice /water barrier if I decide to go open valley.
I also hear some say that nailing the shingles on a closed valley would put the nails near the center of the valley, which would cause it to leak. Im using architectural/dimensional shingles if that makes a any difference.
Just thought I ask. Thanks John :thumbsup:


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## joecaption (Nov 30, 2011)

Installed right a woven valley is far better.
Done right there's 0 reason for any nails to be any closer then 6" of the valley.
Architectural shingle by far are the easiest to cut so there's no seam at the valley.


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## Yodaman (Mar 9, 2015)

Putting the weave in the valley also puts more asphalt in the valley.
A veteran roofer once told me never to put metal down first in the valley because it will cook the asphalt. Not sure if its true or not but I only use Ice & water in the valley under the weaved asphalt shingles.


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## hotrod351 (Jun 15, 2012)

woven is better, but cutting the high side looks better. as for wear in the valley, ive as of yet replaced a shingle roof just because its leaking in the valley. more often than not it because there blowing off or just worn out.


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## Yodaman (Mar 9, 2015)

hotrod351 said:


> woven is better, but cutting the high side looks better. as for wear in the valley, ive as of yet replaced a shingle roof just because its leaking in the valley. more often than not it because there blowing off or just worn out.



IMHO - its a matter of preference which looks better, personally I like the weave because I know its the mark of a quality job.

I have a valley right now that is in need of emergency tar, hoping to buy me another year or two. It is a open, rolled roofing laid over metal construction. Not 100% on the metal but everyone I have ever torn off like this had metal under it.


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## Davejss (May 14, 2012)

I've done both several times. I prefer a woven vally. To my eye it looks better, and it's a bit easier to install. I've also done several cut valleys where one side is run up like it's woven and the other side is cut. That is my prefered method for tight valleys such as on dormers. The cut valleys tend to lay flatter in a tight area.


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## PatChap (Nov 17, 2012)

Woven valleys look rough on laminated shingles. In my climate, I like to use open metal. We usually use 24ga steel, installed properly they outlast the shingles.

We do closed cut valleys on bastard pitchs, running the lower pitch under the steeper.


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## hotrod351 (Jun 15, 2012)

A veteran roofer once told me never to put metal down first in the valley because it will cook the asphalt, was also told the same thing many many years ago. you cut the high side because you get more force from the water running down it. anyway ive always cut them. you run metal then how far back do you cut them from the center, depends on trees and how much other stuff your going to get in there. the wider the easier it is to clean out. i do believe the bundles have instructions on them. found a site that compaires all ways of doing it but wasnt able to attach the link.


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## matt_604 (May 24, 2015)

Yeah.. Metal W-Valley is waaayyyy better. Just use 30lb felt or better underneath, and make sure you have the paper from the deck felt going over the metal by about 6". Then run a row of shingles parallel with the the valley, 2" away from it, after that just cut all courses square so the bottom corner stops at the edge of the valley starter. I don't like closed valleys because the shingles don't lay flat, as soon as they go through a season they get brittle, next thing you know the kid cleaning your gutters out steps in the valley and there is a huge hole there. Would never happen with metal. Also it provides a better channel for debris to be carried off the roof.


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## kmegk9unit (Apr 21, 2014)

Thank You everyone. It made my decision easier to make on what to do with the valley. I will post pic's of the roof when we get it done. 
Thank You Very Much>


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## craig11152 (Jun 20, 2015)

don't hold us in suspense....which way are you going?


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## craig11152 (Jun 20, 2015)

I'm late to the party...too late.... but a copper valley has somewhere between a 300 year and a 2000 year life span. Hard to beat that with a shingle valley, close cut or woven.


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## craig11152 (Jun 20, 2015)

when I first started roofing in 1979 most of our valleys were galvanized metal preformed. Eventually we started bending our own out of aluminum picking colors to compliment shingles. When laminated shingles took over the market we switched to a close cut valley for most of our work. I never did a woven valley and you never much see them in SE Michigan. Maybe its a regional thing.


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## kmegk9unit (Apr 21, 2014)

craig11152 said:


> I'm late to the party...too late.... but a copper valley has somewhere between a 300 year and a 2000 year life span. Hard to beat that with a shingle valley, close cut or woven.


Never started roof. I had to go and finish my daughters roof.


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## kmegk9unit (Apr 21, 2014)

*Not Late*



craig11152 said:


> when I first started roofing in 1979 most of our valleys were galvanized metal preformed. Eventually we started bending our own out of aluminum picking colors to compliment shingles. When laminated shingles took over the market we switched to a close cut valley for most of our work. I never did a woven valley and you never much see them in SE Michigan. Maybe its a regional thing.


Never started roof. Had to go finish my daughters roof someone screwd up. I decided to go with a close cut. One question is, if you have to nail and you cant nail in that 6" margin what do you do? Thats the part that puzzles me.
Im doing a bathroom remodel and helping a family member with a deck at this moment . Hitting the roof next year.
Thanks


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## Yodaman (Mar 9, 2015)

.


kmegk9unit said:


> Never started roof. Had to go finish my daughters roof someone screwd up. I decided to go with a close cut. One question is, if you have to nail and you cant nail in that 6" margin what do you do? Thats the part that puzzles me.
> Im doing a bathroom remodel and helping a family member with a deck at this moment . Hitting the roof next year.
> Thanks



If you weave the valley together the opposing side holds your shingles down, with out nailing or cementing in the valley. If you cut one side then you will need to roof cement under the cut edge. IMO the weave makes for a better valley. When you cut one side you are removing 25% of the asphalt. And if you cut high on the valley its more like 30 to 40% removed. I don't scientifically know that it makes a better valley, but I believe in this case more asphalt is better as the years go by.


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