New roof question

[EddieWalker]

Can you even buy metal valleys anymore? For a very long time, installing a metal valley was considered best practice. But it's been years since I've seen one, and nobody is doing it on new roofs anymore in my area of East Texas.

 

[2515R Dude]

Ok, thanks for all replies and advice. My roof is really steep, so I guess either way is good. So, I will do as locals do.
Thanks again.

 

[EddieWalker]

In my area, the biggest issue that I see with roofers is not installing Drip Edge Flashing. I have no idea why this is so common, but I see it almost every day. And it's why fascia and soffits rot out.

 

[paulsharvey]

It's been 15 years ago; but we used to use 18" roll galv 26ga metal, rolled down the valley, and it wasn't really an exposed metal valley, but it wad there. Problem is, 18", minus atleast 1" of each side, your only 6" on either side, which probably isn't enough to do much. Peel and stick, 24", has the advantage of sealing the nails too, where metal didn't. We never used alum or preformed valleys, back when I was doing shingle roofed apartments.

When I redid my roof, it was peel and stick and weave. Note; my roof is a 4 in 12, no snow load, but wind zone of like 130mph (I pulled that out of my butt, it might be 110 mph?)

 

[not2old]

I spent 30 years repairing condos in greater Vancouver B.C. where it rains forever, and chased large numbers of leaks because a roofer wasn't instantly available. I learned lots from working with them. I believe a metal valley is best but don't use a plain "v". Form the valley flashing with a raised center so that as water runs down the slope, it won't run up the other side under the shingles on the other slope. When the water hits the flashing, it is forced to go vertical and will then run down the valley after losing momentum. Leaks in valleys are difficult to find and a metal valley flashing makes repairs easier as it separates the two slopes. With good materials and good labor, a roof will last a long time today and it's best to try to do a good job.

 

[Racer4]

I spent 30 years repairing condos in greater Vancouver B.C. where it rains forever, and chased large numbers of leaks because a roofer wasn't instantly available. I learned lots from working with them. I believe a metal valley is best but don't use a plain "v". Form the valley flashing with a raised center so that as water runs down the slope, it won't run up the other side under the shingles on the other slope. When the water hits the flashing, it is forced to go vertical and will then run down the valley after losing momentum. Leaks in valleys are difficult to find and a metal valley flashing makes repairs easier as it separates the two slopes. With good materials and good labor, a roof will last a long time today and it's best to try to do a good job.

A lot of the old time roofs (I’m talking about roofs that were being replaced back in the 80s & 90s) had that raised ridge in the middle of the valley flashing. True that it helps divert water down the valley. Another function of that was to relieve stress in the valley sheet. It gave a little bit of leeway for movement from one side of the valley to the other.

 

[yanmars]

What Racer4 said is the valley we used. Not a V but more like a W. That raised part in the center of the valley.

 

[ultrarunner]

My 1983 garage roof shingles in good shape even being 20 year comp...

My valley flashing is failing from acidic organic matter mostly Eugenia leaves...

Only time ever had this and maybe the flashing wasn't good but came from roofing supply.

 

[Midniteoyl]

As said by @paulsharvey , peel and stick, self healing, ice and water shield, then lower shingles ran 6" up the 'uphill' side and the upper shingles overlapping down and cut, like in your 2nd photo. This hides and seals all the nails (assuming they are placed correctly), allows a straight runoff onto the lower roof w/o worry that the water will run up under the shingles on the other side, and if any ice damming does occur, the ice and water shield will still protect the sheathing.

 

[jyoutz]

Either way works. As long as it’s done correctly.