Ok but something is not exactly right because I have NEVER cut my valley tips in my life and my valleys NEVER leak.
I am fully aware of the procedure of cutting them and have been for many years. I just can not find any reason to do so.
Maybe there is another factor in play at the same time on the ones that DO leak?
Most of the time I'm called out to fix a valley leak the cause is someone butted the shingles together too close in the valley.
Like, if its a 3 tab shingle then the middle tab should fall in the center of the valley on the first side ran.
To make this happen you just put either a one tab or a two tab against the run of shingles "away" from the valley and then a full shingle into the valley.
On the last side ran just do not use short pieces close to the valley and don't nail too close in the valley.
Ole Willie:
I know I haven't changed the question of the day. But its been way longer than than a few months. I'll have to finish this and then go look. Every time I think to change it, some new person goes on and posts something. I just love to see what people write.
I thought i'd also post a picture of a typical valley repair. Look where the water went. You can see how it flowed. My total repair job consisted of cutting the tops off.
It's repair work that makes me a believer. I get to see what works and what didn't.
It had metal Paul. THe owner had pulled it out. I had apicture of the uncut shingles.
Willie, I often get calls for valley leaks and find anew roof, I&W and no clipped tops. I just unstick the shingles and cut the tops, problem solved.
Here's a properly clipped shingle.
Here's an unclipped tile roof, closed valley. You can see where the water went.
Here's a slate in a valley. Looks where the water went. This was about 2" from the center of the valley.
Here's a valley that's about 60 years old. No felt under it. Ten inch metal. Never leaked, You can see the water trails. The shingles were clipped like hte ones in the first picture.
Frank, I'm looking at your picture, and there's something I don't get. Wasn't there any kind of metal in the valley? And if so, didn't the metal extend over the edge of the fascia? Or was that picture the result of you pulling off the shingles on the right side of the valley?
I & W has been a blessing to those who never had to seal their eaves, valleys and any roof penetrations the first thing that we were instructed to do down in the State of Florida Dade and Broward counties wa to set a 8" strip of roof mastic at all roof penetratins and terminations just like the use of I&W, also the use of mastic between all metal joints and the correct lap of 3 to 6 inches depending on which wind zone you were in. The mastic acted as I&W before it hit the market place
Are you speaking of cutting out the "valley tips"? That's what they call that around here. I never bought into that philosophy because I've never had any problems with my valleys. But a lot of guys swear to it.
Eighteen or twenty four inch metal here. I&W wouldn't have helped. The water ran all the way across the roof. This is what happens when the shingles tops aren't cut off paralell to the rafters.