Valleys - mesh shingles or cut


#1

Hello,

After visiting this site for the last week, I have decided to hire a local roofing company. I am in the process of reviewing my bids and deciding who to hire. I have learned from this site that my selection should be based more than on price.

I have contractors with different opinions on how to shingle valleys.
One of the contractors says that he meshs the shingles in the valleys and is done - while another contractor says that after meshing the shingles in the valley, he will snap a line down the valley and strike the top shingle only to give it a cleaner look. They both have told me that their way is correct. Hopefully I described this properly as I do not know the proper terminology!

After looking at other newer homes in my neighborhood - most have a cut in the top shingle giving the valleys a line. While one or two homes have the valleys meshed!

Could you please give me your thoughts on the proper way to install!

Also, does it matter which shingle should be on top?

Thanks again!


#2

if by “mesh” you mean weaved…this will void a warranty. a closed cut valley is the install you are looking for. the one that said “snap line” is a closed cut.


#3

Weaving a valley does not void the warranty. There are reasons for all types of valleys and depending on the season, location and type of shingle they are done in various ways.

Just as an example of what two manufactures want and how they look at things differently

GAF
They prefer an open cut valley (valley metal in center of valley). Closed cut and woven are approved and acceptable.

CertainTeed
They prefer a closed cut valley. The woven valley is approved and acceptable as well as the open cut valley (even though they prefer the open cut only be used only on Super shangle and Custom Lok 25 products. It is however acceptable on other material but not the preferred method.

This information came from the current applicators manual for each product.

As far as the closed cut valley method goes a large portion of companies do not install these right. The basic rule is the slope that receives the least amount of water is done first. Then other things come into play such as one slope having a different pitch than others. The other common mistake is that the top corner of the shingles do not get cut back to direct the water out of the valley. Most people just cut one straight line down the shingles. If the top corner is not trimmed back it does not meet the application guidelines

My point is there are a few acceptable ways to do valleys and none of the ones mentioned if done properly would void a warranty.


#4

actually woven valley by all means voids GAF warranty!!! we are a GAF authorized co. and im reading it right now in this years & last years steep slpoe pro field guide. besides…drive around and look at the valleys that have been woven and they are the first to give out due to trapping a pocket of air under them because laminated shingles are too thick too weave.


#5

My GAF book says weaving a valley is acceptable (towards the top of page 150). The only note I have about it voiding a warranty is on the GAF Golden Pledge Warranty (and as I’m sure you know there are other items that could exclude the Golden Pledge Warranty also). There are no exclusions at all in the Certainteed book. We are also a GAF authorized contractor and Certainteed Master Elite Contractor.

What my point is that a woven valley does not automatically void warranties. Your original post was a blanket statement that it will void warranties and that is not the case!

As far as the benefits and draw backs it depends on the shingle and weather. Where I am at because of the temperatures you can easily weave valleys on 30 and even 40 year architectual shingles and it is one of the most common practices in my area. I have yet to see a valley fail before the main field of the roof. Once your into any type of heavier shingle as well as a lot of the liter ones we go with an open cut valley.

My opinion (this is only my opinion) is that a open cut valley on products like Grand Sequoia and Presidential provides the cleanest look. Priming and painting the metal can even give it a nicer accent. I personally do not like closed cut valleys for the look and I have seen to many people install them wrong.

My post is not intended to start an argument, it is just to clarify that most warranties will not be affected. I will agree that there are some cases where what you say is correct but that is more of the exception and not the rule.


#6

both ways work.
if you use the line cut way then make shure the small or lower
side goes first.

gweedo


#7

Never weaved a valley. Did about 300 roofs with closed valley every corner cut and small roof first or 2 or more pitch increase lower pitched roof first. Did about the 300 with open valley as well with a few call backs due to wind driven rain finding it’s way in on the top of the valley. With the closed valley there is no gap for water, leaves, etc to collect.

Have yet to have a valley leak with closed valley. Winterguard down valley felt cut back about 3-4in from point of valley from top to bottom 20in 26 guage galvanized metal. Small roof first with the shingles overlapping a minumal of 1ft past the point of the valley with nails no closer than 6in to valley. Large roof shingled next with a upside down shingle placed a couple inches past the center of the valley to prevent sticking of the new shingles onto the other roof and so I don’t cut into the bottom layer of shingles. When running out of a valley try to offset the shingles enough to not have to go back and cut the top corner of shingle. Hundreds of roofs later it’s works pretty good and it don’t leak.

In MN and WI if the roof is near to pine cone trees I may install painted to match the shingles open valley. From time to time a h/o will insist on open painted valleys and usually they get what the want!

Good luck and don’t go with the lowest bid unless he’s known to be a good roofer.

BTW, don’t weave due to the fact of most three tab shingles will curl over time in the valley and that’s a spot you don’t want lifting up. Also houses can move and shift a little especially brand new ones so making one or two seperate cuts in the valley is better, IMO. Plus with weaving you have to go back and forth so much.


#8

i was not trying to start an arguement either. and in my travels i have noticed that roofing practices vary greatly by just crossing a state line. in NY 99% of roofs are closed cut valleys. in north carlolina they dont even use drip edge.


#9

a weave is a stronger valley, no doubt about it. It’s also more work and not a short cut. You seem to be cut from the architectural shingle mould, and I am also. When you weave with architecturals, it is esthetically unpleasing, and might have some negative drawbacks. But if you are using 3-tabs or jetway shingles, a weave is a better product.


#10

You are right about that. I still run across the occasional job that has been speced out to put nosing on top of the shingles.

I started roofing in high school back in Iowa. Moving to California and seeing the difference between the areas was amazing. Then the changes that have occurred in the 27 years I have been out here.


#11

I’ve traveled to every corner of the nation but the South East and most states in between and you do see a lot of different stuff. In the North East for example lots of steep metal roofs or steep roofs with ashpalt shingles with metal on the eaves a couple feet and 1-2ft of metal in the valleys. My first thought was for snow/ice run off.


#12

One of the contractors says that he meshs the shingles in the valleys and is done -

This is a woven valley and is NOT allowed on GAF Golden Pledge warrantys (bottom of p185 in the GAF manual). It’s an antiquated method that very rarely has a use in my opinion. In 15 years of roofing I have come across maybe 10 instances where I HAD to use a weave. Nothing wrong with it, nothing better about it. It MAY leave a slight hump on either side of the valley due to material build up making it unsightly.

while another contractor says that after meshing the shingles in the valley, he will snap a line down the valley and strike the top shingle only to give it a cleaner look.

This is a closed cut valley and it’s what all us guys under age 90 use. It installs faster, looks better and is much, much easier to repair should the need arise.

Bottom line it that neither application is “wrong”.


#13

Just pay up and use galvinized steel.


#14

galvanized steel rusts out once the finish gets worn. Once again, we’re in disagreement. Aluminum does not rust. Copper does not rust. Lead does not rust. You need to hang with more roofers and less builders.


#15

Shaking my head again.


#16

nice to meet roofing buster and doug k1.
hope to read you more.
like to see new areas represented.

sorry didnt mean to but in there.

gweedo


#17

[quote=“Doug K1”]

You are right about that. I still run across the occasional job that has been speced out to put nosing on top of the shingles.

I started roofing in high school back in Iowa. Moving to California and seeing the difference between the areas was amazing. Then the changes that have occurred in the 27 years I have been out here.[/quote]

The biggest diffrence ive cam across was i went to Vancouver. They use metal under the ridge cap. Ive never seen that before. I ve also seen some crap work in Saskachewan where the valleys are caked with tare. I was checking this house out and there wasnt even any starter.
Id like to take a trip to the staes and see how the roofs are done.