# Dormer base flashing



## Tcattco (Oct 24, 2021)

Hello everyone, I have been beating my head against the wall for a few years over this one and greatly appreciate some expert advice. I attached a pic of my house mod below.

Shingles were new 5 years ago. Ice and water correctly placed around dormers, dormer valleys, and down entire line where house roof meets porch roof pitch. Dormers are step flashed correctly. The snow gets deep on the dormer side of my roof. When it does it insulates the heat loss i have where porch roof meets house. Ice dam forms along entire line where porch meets house. Water works its way back under dormer base flashing and must find a nail hole in the ice and water. Water drips down exterior house wall where porch meets house. I also sometimes get a leak down exterior house wall right over porch door. This has occurred since roof was new. This also doesnt happen until late Jan/Feb after the snow gets about 3 1/2 feet deep on that side of the house.

This is a log home and cant be insulated anymore than it already is. It is also a nonvented roof with cathedral great room. I spray foamed every gap between wall and roof line. Roof over house consists of SIPS and all gaps are spray foamed. Roof over porch is 2x pine t&g.

Question is, can I seal the dormer base flashing where it sits on top of shingles? If so, what is a recommended product? Also, other than using heat tape is my only option to keep the snow shoveled off?


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## roofermann (Jul 7, 2012)

Worth a try, would use a urethane based caulk to do so. Your local big box should carry the PL brand.


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## Tcattco (Oct 24, 2021)

Thank you for the reply. Is the PL brand better than Solar Seal?


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## roofermann (Jul 7, 2012)

Solar seal or NP-1 are maybe better, IMO. Just the PL is easily available to home owners


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## Tcattco (Oct 24, 2021)

Thank you!


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