Open Valley?

JTW

So I see the copper in valleys done a couple ways, wondering what the pro's and con's are in your opinion, I see straight(simply formed to fit the valley, and I see some with a V or W bend in the depth of the valley??? I ask because I was in Woodstock VT( a high brow area for those who are in other parts of the country) most all of what I saw there was simply formed to the valley and most of what I see in new work is the V style.... I am guessing it has to do with controling watershead?

johnk

The w in the valley helps the water from going side to side.

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"A Roof is only as good as it is Applied"

woodchuck2

For the few rooves i have done i left it up to the customer which way they wanted to go. The V does help with water shed but not everyone likes the bend in the metal. Some folks prefer the metal to just blend into the next roof. Personally i have never done the W form and it isnt something you see around here.

tekwrytr

The W is common in wood roofs (shake, wood shingle) because a fast runoff can cross the valley and wood roofs only have paper to keep the water out. Shingle and tile (or slate, or whatever) can be smooth across because a secondary seal is used; mineral surface roll underlay, plastic cement bedding, etc.

There are lots of W valleys on asphalt shingle roofs, usually installed with a secondary seal. There does not seem to be a whole lot of purpose in W valleys for asphalt shingles, aside from an opportunity to display nice straight lines and a slight flare at the eaves.
Thanks

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http://www.tekwrytrs.com/roofing/

2ndGen

Oh. I always thought it was in homage to the former President.



Personally, in a heavy rain that can work it's way "up" the opposite's side shingles,
water will get across that little peak without a even trying hard.

For shingles, I don't use open valleys at all.

It's kind of hard to figure out the benefits of a peak in the middle of a valley.

If it's too high, it's a hinderance to water flow and in heavy rain could cause water to flow back up into the valley.

When working with natural materials (wood, slate, tile, etc...), there is so much room for going overboard with the under valley protection that open valleys are ok there, but in a shingle roof, that option's not feasable. It's enough to just get the overlap from one side to the other nice and level so's not to cause any noticable lumping.

Whatever.

I've been doing it for a couple of decades with no problems, why fix it if it ain't broke?

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"I've been up on the roof. I know what those guys go through.
My whole life has been about making that profession respectable."
Ken Hendricks
www.SolutionsRoofing.com

MrRoofer

About the only time we will use W valleys is when we have two different pitch of roofs, ie a 12/12 dormer on top of a 4/12 main roof. The size of the crimp depends upon the size of the roof (bigger roofs = bigger crimps doh). Having said this, I find this method is only a mild deterrent, because with heavy downpours you're going to need about a 2' crimp anyway .

Closed valleys are a thing of beauty yup, however I do realize closed copper valleys probably don't exist .

The only other time we use it is when it gets requested.

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'I'm living on the edge!'

2ndGen

I like to think of them as "peace of mind" valleys.

__________________
"I've been up on the roof. I know what those guys go through.
My whole life has been about making that profession respectable."
Ken Hendricks
www.SolutionsRoofing.com

tekwrytr

I worked in south Florida some years ago (Dade and Broward), and "W" valleys were standard on asphalt shingles. An extra layer of 30 lb. felt under the valley, a layer of 90 lb. mineral-surface roll, then the metal valley. A layer of asphalt cement was troweled up the valley edges a few feet at a time (to avoid surface glazing), the shingles continued into the valley (with no nails in the metal), cut to a line with a hook blade, the top corner clipped, and the ends pressed into the fresh asphalt cement.

As each run of shingles hit the valley, the end of each individual cut shingle had to be gently peeled back, and a layer of asphalt cement gently and carefully applied to the blind end of each shingle, with the overlapping shingle then pressed into the fresh asphalt cement.

A royal pain, yes. But it paid very well, there were zero leaks, and the company I worked for got premium prices in a highly competitive market because of it. For those of you unfamiliar with south Florida weather, wind-driven rain that runs uphill is not at all unusual.
Thanks

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Commercial EPDM Rubber Roof Repair - Maintenance - Re-Roofing Exclusively. Serving the Twin Cities, MN Metro area since 2001.
http://www.tekwrytrs.com/roofing/

2ndGen

Hi T.

How well or not do closed valleys work in FLA?

I know different regions have different standards, but I was curious to know if some study had been done to determine that open valleys worked better down there.

I would assume that if closed valleys would be preferred there, especially in FLA where wind can get under the open shingles and blow them off, it'd be worse down there for open valleys.

Plus, no ice damming.

__________________
"I've been up on the roof. I know what those guys go through.
My whole life has been about making that profession respectable."
Ken Hendricks
www.SolutionsRoofing.com

tekwrytr

To the best of my knowledge, closed valleys are not an option in Florida (or at least were not an option when I worked there). The alternative to the "W" valleys was a conventional open valley--90 lb. mineral surface roll over 30 lb. felt centered in the valley, shingles trimmed and clipped to leave center of valley open.

Biggest problem was (and still is) sloppy workmanship. Valley shingles were cut with utility knives (rather than carefully with hook blades), often cutting through the 90 lb. Obligatory plastic cement was troweled up the entire valley at one time, allowing the surface to partially cure, or to be covered with dust, defeating the purpose. Similarly, the valley shingles were rarely lifted for the added seal between courses at the valley. When you bed only the shingle ends in plastic cement, only the top 5" of each subsequent course of shingles contacts the asphalt cement. The "center 2 inches" has to rely on the shingle adhesive for sealing. That is totally inadequate for Florida weather, and frequently resulted in valley leaks.

There is no question that woven valleys offer superior waterproofing if installed properly (no nails close to the center of the valley, etc.). There is also no question that most people are followers; if open valleys are typical in the area, selling closed valleys is tough, regardless of whether or not they are better.
Thanks

__________________
Commercial EPDM Rubber Roof Repair - Maintenance - Re-Roofing Exclusively. Serving the Twin Cities, MN Metro area since 2001.
http://www.tekwrytrs.com/roofing/

jaros bros.

Another reason for the "w" is to prevent distortion from being noticeable when you get really hot or cold weather. I always preferred the open valleys for looks. I snapped two lines and cut every shingle before I nailed it down. Afterward, I went up the roof with the PL roofing caulk and sealed everything up well. Depends though, it has to go with the house. Never ever weaved shingles because they deteriorated too quickly it seemed like and were prone to leaking. I like to cut if I'm not going to have valley metal.

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Josh Jaros www.jarosbros.com Remodeling in The Woodlands, Texas

smeagol

[quote=MrRoofer;675789]About the only time we will use W valleys is when we have two different pitch of roofs, ie a 12/12 dormer on top of a 4/12 main roof.

This in my opinion is where a closed valley is more reliable.(given you obviously shingle through the 4/12 first)

tinner666

A 'W' valley has no real use when 12/12 is over 4/12 for instance. If you want to prevent water from crossing, use the ole fashioned 'Channeled Valley'. You can set the channel for whatever width you want, and the seam can be set at height wanted.
An example.
The one with the Ternak slate has a 2" channel, 2" seam. 12/12 over 3/12.

The one on the picnic table is a mock-up showing the differences. The little piece is a typical W. The slate sit higher than the seam. The larger piece shops how the channel directs the water and prevents it from jumping. Really useful on 18/12 over 3/12, for instance.
I should have bent the other side of the W at 45 for clarity, I guess.

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Frank Slate Roof Repairs, Richmond, Va.

MrRoofer

Agreed. For the most part closed valleys are employed, it is only upon request that we do W's.

With shingles and regard to pitch changes, I don't recommend open valleys period. As I said before, you need a pretty big W to prevent water from jumping in the event of a very large rainstorm.

To get a Certificate of Assurance from the ARCA here, with open valleys you are required to use a W valley. Not that I put a lot of stock in the C of A, as it requires a journeyman roofer to have installed the roof (ticketed shingler, for which no ticket can be obtained ), and on pitches over 8/12, underlay is not required, which in turn tends to void the warranty on most shingles. Damn I hate pompous roofing dinner clubs .

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'I'm living on the edge!'

MrRoofer

In essence could the same effect be achieved by simply adding an extra W to the steep side of the valley?


Nice lookin slates

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tinner666

Maybe. Why bother with the extra break?
First one is an existing about 70 years old, 3" channel, closed on other side. No felt, Ice&Storm, under it. 1" seam. 14/12 x 4/12. Working fine.
2nd is about 85 years old. No felt under it either. 12/12 x 7/12.

With the steep pitch, channeled makes much more sense. I've been up on this type during intense downpours to watch them work. There is something to be said about the old ways when you needed to know how to roof with what you had. I've seen a few of these well over 100 years old working fine.

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tinner666

Ho wdo you like this Cali-cut valley.

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Frank Slate Roof Repairs, Richmond, Va.

MrRoofer

I just figured from the picnic table shot there was two pieces of metal, I thought I'd simplify it into one...or is that shot not how the finished product looks (ie the W should be tight to the slates)...forgive my naivety.

The channel idea makes way more sense for sure. I have limited experience with slates so that is a new one on me, even the ssr and concrete tiles I've seen have all been 'valleys' and not channels. I would have to think the height of the channel wall would be less than the profile of the roof material for this system to work properly, and even so, I imagine a limited amount of water is going to hit that vertical piece of channel and work its way back under the 'slate'.

At the end of the day, if it aint broke dont fix it. Everybody wants to be a mechanic these days tho.

That last shot looks like a joe-blo-Ho special. Wonder what the reason for selling is .

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tinner666

Yes. it's supposed to show the difference. I made the scale a bit large for effect. Here's the pic without that other piece in the way. It swings up and can be seen to the upper left. I cobbled it together at a site to explain why and what I was going to do.

Here's another oldie, but goodie. Crooked as crap. One I replaced is also crooked.


This one, the HO worked with me. We pulled the slate, and just put them back where they came from. Didn't bother to straighten the look.


That other pic is just some of the typical JL stuff I see everyday. I'd need a camera with a terabite of memory to take shots in just one day.

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Frank Slate Roof Repairs, Richmond, Va.

tinner666

The seam can be the height of your choosing, dictated by looks, function, and height of the material being used. Hendricks tile are almost 2" high, layered on the roof.
Same for the channel width.

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Frank Slate Roof Repairs, Richmond, Va.