Final question on topping out valleys
Okay, finishing up a major reroof (replaced broken rafters, sistered new 2x6s to each existing 2×6 rafter (24″ o.c.), redecked with 23/32″ – 4:12 pitch in deep snow country.
Im struggling with a few questions relating to the valleys on dormers.
1. Topping out the flashing. The first two pieces of flashing made it to the ridge.
http://webpages.charter.net/baddoglt/Valley.JPG
How do I finish the flashing? Piffin gave me a suggestion on the 12th, but I am having a hard time visualing it.
Do I trim the tops of the flashing parallel with the ridge, or leave them square and only overlap the corners? Am I missing it entirely?
2. The answer to (1) leads to, how do I shingle over however I do the flashing? Using 50 Year Corning Oak Ridge architectural shingles and doubling up hip and ridge shingles on the ridges..
3. How close to the ridge of the W should the shingles be? I’ve see shingles as close as touching the ridge of the W and I’ve read distances as big as 4 inches.
I’ve been searching the web for photos or illustrations for days, and everything is related to in the valleys, not at the top. I can provide a fax number by email too.
Thanks for any ideas. I am on the brink of calling a roofer, but (with the exception of setting a girder truss), I’ve pounded almost every nail myself, and really want to finish things myself.
-Curtis
Replies
Visualize a verticle line continued up the plane the ridge lands on from the ridge. Cut your valley flashing on each side so it crosses that line by a couple of inches. Install one side and snip it where you have to to let it fold down the other side of the valley. Repeat on the other side and solder or caulk as necessary. My favorite resolution for this detail is to continue the ridge caps across the valley tops and bury them under the first course of shingles on the other side. This eliminates the potential for water coming down the big plane finding its way under the ridge caps on the other side of the valley.
I invented visualizing verticle lines.
I was having a hard time finding words to explain it verbally so I waited to have time to draw it up for you.
The blue lines are the sheathing cuts dfining the valley and ridge.
The brown lines represent the valley itself - run it past the ridge.
The red lines represent the cuts. Make cuts there so the valley maetal lays across the ridge about two inches and snip/fold at the center.
Now do the same from the other side, with a bit of Geocell between metal laps as you nail it down.
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Awesome!
Piffin and Greencu, thank you very much.
Curtis
Okay, back from the big box stores - no Geocell. Stood in front of the caulk displays, three choices.
1. Henry 209 Elastomastic
2. DAP Gutter and Flashing Butylflex
3. GE Gutter & Flashing Silicone II
Bought them all, will return what I don't choose. Any preference among these? We see a couple days below 0 each winter, and a couple of days in the 90s each summer, low humidity.
Curtis
Gotta go to a roofer's supply store to get Geocel. Make sure the sealant you choose out of the three you bought is not corrosive to the metal you're using. The Henry product (although I'm not familiar with this specific product) is probably the most likely.
I invented black mammy.
i'm not familiar with the Henry's but I used tio use butyl a long time ago, until I met geocel, It works good with metal, but is nasty to get on you - like chewing gum on the bottom of your shoe.
Anything but silicone.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!