Q: I need to re-shingle the roof on a home I just purchased. I am familiar with the basics of the job, but I'm not sure how to tie the main roof shingles into a dormer roof. Could you please offer me some advice on this subject?

A: How are the valleys shingled now? Generally I prefer a closed valley shingling. They look neater. When the shingle reaches the valley, let it bend up along the dormer roof. (Don't cut it at the valley) Then do that course of dormer shingles with the same over lap on the main roof. You alternate back and forth with them using the shingles to cover the valley.

Q: I have a brand new home, with a new large porch that is dormered and the roof connects on the upward/backward slope of the house. I would like some on formation on shingling the valley where the porch joins the house.

I don't want it to leak and want to do the right thing up front. Since the porch is new, I need to know what products to buy, like flashing, caulking etc. and some step by step. Any ideas out there?

A: There are two ways to shingle a valley, open or closed. Closed looks much better. It is made by weaving the shingles and presents an unbroken shingle appearance. Open is easier, and is less likely to leak. So, it's your choice. Both are described on every package of shingles. For either, you will want to run a strip of building paper up the valley on top of the other paper.


With an open valley, you will want at least a 10" wide strip of flashing running all the way up the valley. The shingles then end about two inches from the center of the valley on either side. With a closed valley sometimes the flashing is left out, but in any case the shingles are alternated bent up and weaved.