Better to do open valley or closed with Timberline HD?

Am I better to do an open valley with painted metal or closed valley with Cslifornia cut? And if I do closed valley, do I need metal in valley?

Thanks

[quote=“rogersmithiii”]Am I better to do an open valley with painted metal or closed valley with Cslifornia cut? And if I do closed valley, do I need metal in valley?

Thanks[/quote]

Given those options I would go with the open metal valley.

Your standard closed-cut valley is a good option, not the shortcut California style…

What he said ^^

Agreed, open metal valley is the best “option”.
And no, you don’t need metal if you do a closed cut valley.

Another option is a laced valley where one shingle is ran across the valley from one side and then one from the opposite side, back and forth all the way to the top.

As long as a skilled professional is the one doing the valley, it’s a personal choice and there should not be a problem with either of the 3 styles.

Metal or Ice and Water Shield is desirable in the valley before installing the shingles. Especially in cases where the wood in the valley is rough cut and does not make a smooth transition from one side to the other.

I thought California cut was the same as closed valley. What is the difference?

gaf.com/Video_Library/0_darpmmhd

Found this on the web. Interesting viewpoint.


Q. Do you have an opinion on open vs. closed roof valleys? I’ve had six estimates done, and all of the higher estimates cite open valleys (with a metal flashed valley), while the lower estimates cite a woven “California cut” valley. My opinion is that a California cut valley, with heavy Vermont snow loads, would cause the shingles to stretch (stress) and cause fissures to open. Regardless of open or closed, this of course presumes that a Grace water/ice membrane is used. I further feel that an open metal valley would flush faster, without wearing away the granules.

In looking at the Fabral metal roofing supply catalog, it has a valley flashing that from the end looks like a “W.” That center point (only about 1 inch high) actually minimizes the wash effect of a larger surface area hitting the valley and washing up the adjacent roofline.
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A. Woven and close-cut valleys are indeed vulnerable to early wear for the very reason that two roofs are draining down them. The protective mineral granules wear out faster and expose the asphalt medium to the damaging UV rays of the sun.

But this is not the only problem with these valleys. They require extreme care in their installation, and it is not possible to make sure this care was taken, as three steps are concealed and not visible.

In my many years of inspecting roofs, I haven’t seen many such valleys done as they should be. Roofers like woven and close-cut valleys because they are faster to install than metal valleys, but the best roofers I know use metal exclusively.

Grace Ice & Water Shield or its equivalent should be installed in the valleys and at all roof perforations. It is even becoming more common for contractors to cover the entire roof with this membrane, although there are arguments against doing so.

Fabral’s valley flashing is the way all valley flashing should be. The inverted center “V” is popularly used in the Northwest, but not commonly used in the East. This inverted “V” prevents the water from a larger roof plane or one receiving more water because of the wind direction from running over the weaker roof plane. Its hemmed edges are to secure its installation with clips to allow for expansion and contraction; valley flashing should be nailed only at the top.

I suggest you consider only the roofers using metal valleys. And if I may add, getting six estimates for a roofing job is excessive; three is normal. Preparing estimates is costly for contractors, and the chance of getting the job diminishes in relation to the number sought. More than three estimates are sometimes requested on much larger jobs designed and handled by architects, but even this should not be common practice on residential work.

[quote=“rogersmithiii”]Found this on the web. Interesting viewpoint.


Q. Do you have an opinion on open vs. closed roof valleys? I’ve had six estimates done, and all of the higher estimates cite open valleys (with a metal flashed valley), while the lower estimates cite a woven “California cut” valley. My opinion is that a California cut valley, with heavy Vermont snow loads, would cause the shingles to stretch (stress) and cause fissures to open. Regardless of open or closed, this of course presumes that a Grace water/ice membrane is used. I further feel that an open metal valley would flush faster, without wearing away the granules.

In looking at the Fabral metal roofing supply catalog, it has a valley flashing that from the end looks like a “W.” That center point (only about 1 inch high) actually minimizes the wash effect of a larger surface area hitting the valley and washing up the adjacent roofline.
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A. Woven and close-cut valleys are indeed vulnerable to early wear for the very reason that two roofs are draining down them. The protective mineral granules wear out faster and expose the asphalt medium to the damaging UV rays of the sun.

But this is not the only problem with these valleys. They require extreme care in their installation, and it is not possible to make sure this care was taken, as three steps are concealed and not visible.

In my many years of inspecting roofs, I haven’t seen many such valleys done as they should be. Roofers like woven and close-cut valleys because they are faster to install than metal valleys, but the best roofers I know use metal exclusively.

Grace Ice & Water Shield or its equivalent should be installed in the valleys and at all roof perforations. It is even becoming more common for contractors to cover the entire roof with this membrane, although there are arguments against doing so.

Fabral’s valley flashing is the way all valley flashing should be. The inverted center “V” is popularly used in the Northwest, but not commonly used in the East. This inverted “V” prevents the water from a larger roof plane or one receiving more water because of the wind direction from running over the weaker roof plane. Its hemmed edges are to secure its installation with clips to allow for expansion and contraction; valley flashing should be nailed only at the top.

I suggest you consider only the roofers using metal valleys. And if I may add, getting six estimates for a roofing job is excessive; three is normal. Preparing estimates is costly for contractors, and the chance of getting the job diminishes in relation to the number sought. More than three estimates are sometimes requested on much larger jobs designed and handled by architects, but even this should not be common practice on residential work.[/quote]

The problem with a California style valley is that it is an inferior way to accomplish a simple task, it is faster that is all.

Roofers that use this type of valley are solely concerned with speed of application and other shortcuts are usually found all over the roof.

Whenever I see a California style valley it is a good indication of substandard workmanship, so far this has been true 100% of the time.

To the point, Roofers that care about what they are doing don’t use California style valleys, there is a reason for this.

I&W underneath and 26ga prepainted steel. 6/12 pitch and over I would recommend a “W” style valley.