# Dead Valley problem Help!



## Waldochza (Jan 22, 2017)

Hello, 
I'm looking for advice on re-roofing a section of our roof where a valley meets a wall. Valley is 15 feet long and the last foot of the valley water will slam into the wall. I had the contractor install a w metal valley to prevent to much run off but now during winter the lower slope towards the end of the valley is causing some major ice damming and has actually caused a small leak in my garage. Thankfully caught the leak before it caused any damage and removed the ice dam to prevent further damage at this point in time. I am looking to rip out the entire valley and redo it. What do people recommend for something like this? Would a rubber membrane or low slope roofing product be my best bet and if so which ones do people recommend? How would I cut the membrane off if the valley ends onto shingles. I have attached several photos. Sorry these were taken showing the ice damming but if anyone has suggestions or ideas they would be greatly appreciated and if you need more pics just let me know. Thanks


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## jlhaslip (Dec 31, 2009)

When you tear off the roof, over frame a cricket which will divert the valley run off away from that wall so the valley runs free to ground.
In the mountainous area where I used to live, roofs were often completely covered with a "bituthane" product that sealed onto itself and you could drive nails through and the product would seal around those nails. 
If you redirect the valley with a cricket and use a full coverage roof sealing product, you will avoid a whole series of issues.


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## carpdad (Oct 11, 2010)

Not sure of the angles but could be poorly planned angles for drainage. Cricket may help but it depends on the angles and crickets are usually covered with one piece roofing or flashing that becomes no seam water barrier. Cricket valleys are also extended with ice shield min 3' both ways for more than possible water that flows sideways. In your case it may be hard or impossible to add insulation/vent. Water also flows uphill if the conditions are there. I would add ice shield or rubber roofing for the entire roof which would climb over the wall (remove the gutter-you don't need it there) and extend 6' on the butting roof. What you want to do is cover the entire area without seams so that water flowing up, down and sideways will not find a seam somewhere and leak down into the framing/space below. Then reroof with shingles for the visible part. I would go that far because of the drainage angles and subpar insulation/vent. For the wall part, metal flashing painted to match and tack with roofing nail. 
When I say subpar insulation, I mean that unless r60 or better that can keep some distance between heat and cold (also without air moving around inside), and this is almost impossible for normal houses, you will have ice dam and best defense is seam less and wrap around nails.


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## SeniorSitizen (Sep 10, 2012)

Failure to provide drainage for water that's under the ice allows water to enter the structure somewhere every time.


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## Windows on Wash (Aug 30, 2011)

Ugh.

We see this stuff all the time with additions. Sad thing is, there is always a way you can do them without creating this future nightmare.


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## craig11152 (Jun 20, 2015)

Its hard to tell from the pictures but here is one thought I have...


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## carpdad (Oct 11, 2010)

Not sure if the angles are that acute but valley is valley. If op has enough snow to bury the valley and go over the next roof, he's going to have leaks. My guess was even if he has a great lake up there it would be contained. Guessing the garage wall and house roof meet at the peak. For water both wall and roof will need one piece flashing and step flashing has too many holes. For ice heating cable may help.


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