Roof flashing around outside corner

[magichammer]

Hello,

I'm hoping someone can suggest something for a problem we have with our house. We live in a split level with a new addition off the back and where the roof of the lower level meets the wall of the upper level, we get a lot of ice dam problems in the winter.

The lower level roof actually follows the wall down to the corner on a 4-12 pitch, and the roof of the addition actually goes around the corner and continues downward. As I mentioned, in the winter we get a lot of ice dam problems in this area and are getting water damage in the house.

We added 18 inches of insulation to minimize heat loss, but the melting snow on the roof continues to cause trouble.

Short of reconfiguring the entire roofline, is there a way to either purchase prefomed outside corner flashing or construct my own flash to keep the ice from getting into the joint between the roof and wall?

I asked at the local big box store, but they were stumped. I can't be the first person to have this situation.

Thanks for any suggestions.

Greg in Minnesota

[pushkins]

In situations like yours I always run my flashing up 12" behind the siding and I seal any joints of the flashing.
Without a picture of your exact situation it's kind of hard to make a recommendation, you can buy 16" wide rolled sheet metal and fabricate the 90 degree angle or rent an aluminum break (used by siding guys), however to install it your going to have to remove siding and shingles.
Another option would be to add a 12" wide piece of flashing over the top of the existing flashing, make sure you overlap the two by at least 2" and make sure you seal the two together with an asphalt sealant.