I’m doing a tear off and re-roof on a 4/12 pitch roof and debating woven valleys versus copper valleys. Which is better? Seems to me that the woven might be more water tight initially, but that the shingles in the valley might have shorter life since the amount of rain in the valley might tend to erode the surface aggregate more. What do you think?
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Replies
Chuck,
I haven't used either method, but from what I've read on this board I think you have made the choice to be between the worse possible valley method and the best valley method. I usually use a California cut. But given your choices, go with the copper.
Rich Beckman
Another day, another tool.
Can you enlighten a non-roofer? What's a California cut? Is that where you run the shingles from one roof plane over onto the other and then trim the shingles on the other side to the valley? Any ideas as to why some valley methods are better than others?
"What's a California cut? Is that where you run the shingles from one roof plane over onto the other and then trim the shingles on the other side to the valley?"
That sounds like it.
"A large number of the service calls I get are leaking california valleys. If installed correctly, there's nothing wrong with this type of valley."
Well, clearly, any method will work better when installed correctly.
There was a good article in FHB #152 (Dec '02/Jan '03), "Four Ways to Shingle a Valley".
Finally, although it is true that, based on what I've read on this board, I would say the woven valley is the worst valley, but...based on what I've seen in the field, there is an equally poor choice...A roll roofing valley.
Rich Beckman
Another day, another tool.
lol fer sure specially on a 12/12 for a repair
If you can afford the copper and plan on staying in the house use it ,it will outlast the shingles and can be reused on the next shingle installaltion.The best way to install is a w style 18" wide valley that is held in place by clips on the outer most edge
A large number of the service calls I get are leaking california valleys. If installed correctly, there's nothing wrong with this type of valley. However, there's a lot of small things that can go wrong. Not running the bottom side far enough up, nailing too close to the center, etc. With today's supposedly longer lasting shingles, it'd be false economy to not use copper.
Lay the valley with cleats as mentioned above. Overlay each piece by a minimum of 6" ( more on low slopes). A trick I often use is to run a course of shingles parrallel to the valley center line at what ever reveal I want in the valley. Then run each shingle course so that the bottom corner of each hits the bottom edge of the valley shingles. This produces a nice straight no cut valley.
Realistically, any of the 3 can work well.
What you want is a valley that lasts one day longer than the roofing material used. Is this valley going to be the weakest link?
So a thick copper valley might outlast 2 roofs. Do you care?
Like with most things, it's the details that really count. These ice & water membranes certainly do make up for a multitude of sins...
>>Realistically, any of the 3 can work well.
For how long?
>>What you want is a valley that lasts one day longer than the roofing material used. Is this valley going to be the weakest link?
And a valley made with the same material as the rest of the roof will not last as long as the rest of the roof in any area with significant rain.
QED - a valley with shingles will go first beccause of the cocentrated water flow.
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> a valley with shingles will go first beccause of the cocentrated water flow.
It's worse than that. Not only is the water flow concentrated, but because the wind drives the rain, the amount of water coming from one side of the valley will often be greater than the amount coming from the other side. So water doesn't just go down the valley, it wants to cross the valley and push its way in under the shingles or tiles on the other side. A "W" shaped metal valley, be it copper or galvanized, will do better than any kind of shingle only valley against that problem.
-- J.S.
One other point: If your gutters are not copper, then I wouldn't use a copper valley because of electrolysis (sp?).
No question in my mind.
Metal valley lasts longer than the shingle valley
Copper lasts longer than AL or Galvanized.
of all the shingle valley methods, woven is the worst, IMO.
One more point against weaving this time of year, if it is too cold to bend the shingles easily, they will fracture and leak.
Excellence is its own reward!
And, for whatever it's worth, when you see a copper valley, you smile and think positive thoughts.
I like the peace of mind that comes with them as well.Jake Gulick
[email protected]
CarriageHouse Design
Black Rock, CT
The artist in you is leaking out.
Truth be known, if I were to rank valley methods , weaving would be on the bottom of the list, both in terms of appearance and quality
.
Excellence is its own reward!
Chuckling, so true....Jake Gulick
[email protected]
CarriageHouse Design
Black Rock, CT
I have 2 1/2 year Tamko's that are wooven in the valley and they are'ra cracking. Piffin where were you when I needed you!! Ha ha
What kind of shingles are you going to use? Forget woven valley if you are using architectural shingles. Also a woven valley tends to collect more debris especially on a shallow roof and that tends to hasten the demise of the valley shingles.
Copper rules.
copper is best if mony isnt a factor.weaving can be fine if ice and water sheld is used but copper is better .and looks great also. dogboy