Cutting dog ears off off valley's

who here does this on closed valley’s. for the ones who dont, have you ever seen anything happen to the valley even though you cement down the center of the cut side valley. have you seen water travel to the center?

i do it on every valley always. open or closed doesn’t matter. I hope tinner sees this. I know he has seen water travel in. You can the water stains on the back of a valley shingle when you tear one off thats not cut.

They’ll leak, even if cemented. Why on earth would you use cement in a valley? The cut side is never less than 2" away from the center anyway. Preferrably 2" at top, tapered to 3" or even 5" out at the bottom. The exact taper is determined by valley lenght and asthetics.

Yeah always cut them here, some guys dont and think Im wasting my time but I really don’t care what they think. Same with the tapering which I dont get why people argue, its very simple common sense as you move down the valley more water travelling down the valley therefore larger taper.

We snap a line (with blue chalk so it does not stain) and cut it perfectly straight (open or closed). I like the slight taper going down the valley, too.

Exactly how we do it, we stay away from the red chalk.

always cut my valleys. however i heard you don’t cut them in ice and snow country.does this cause ice damns. i’m from the south and was wondering if that is true or not.

I would bet my right arm this isn’t true.

There has never been a time when I am working on a valley that I do not cut the shingles.

Out of curiousity, everyone runs starter up the valley right?

cement in the valley is code here in sunny Florida.

[quote=“BAMBAMM5144”]There has never been a time when I am working on a valley that I do not cut the shingles.

Out of curiousity, everyone runs starter up the valley right?[/quote]

I’m not sure I know what a valley starter is.

i think some of you guys are confused. its not the shingles were you snap a line down the center. is under the shingle on the top side of the valley. you don’t see it and you certainly don’t snap a line to cut it.

They were talking about the small cut off on every shingle, and the technique that they use to cut the whole length of the valley.

We never run a starter up the valley. That is a california valley, I can’t stand those personally. But too each his own. Nothing against those who do it.


Snow country is no different than elsewere. Cut the top corner. I believe on most shingle brands it is on the instructions.(Not really sure)


We always cut the ears, never tar. No problems. Cut the ears also when butting to the side of a roof vent.

Anyone cut them on rake edges?

Around here everyone says cutting the “tits” off the valley.

Im surprised no one else here does that. How do you make sure the shingles seal into the valley? I am talking about running starter shingles vertical in the valley leaving your two inch space from the actual “W” so that you can cut your shingles nice and straight and give them something more to seal down to.

I would love to post a picture but unfortunately this site does not allow that to work unless you want to fuss around for an hour.

I know what you’re talking about Bam. I have used the same technique on open valleys in the past. I like it on a closed valley because it gives you a guideline that you can cut as you go, but it leaves a hump on 3-tabs.

He is not talking about a California valley, he is installing a bleeder shingle as a straight edge and the added benefit is a glue strip running the length of the valley. Very few roofers use it from what I have seen.

And yes, we always dog ear our valleys. I just bid a large repair for a customer and dog earring all of the valleys is part of it due to leaks caused by water tracking under the shingles.

ya mean like this-

I understand what you were saying Bam. I use that technique when I am shingling around…lets say a skylight that has a one piece flashing. I gotcha.

As far as cutting the “tits” of on a rake. I can’t see the benefit of doing that. Seeing as there is no need to divert water that isn’t there.

A california valley basically negates the cutting off of the corners. Because the water will track right under the shingles the same way it would if you didn’t cut off the ears. Same exact principle.