How To Correctly Build A Roof With A Valley

For example install valley boards flush with the rafters not on top.

How to correctly build a roof with a valley.

It is important to get the roof construction correct at the valleys. How to shingle a valley with architectural shingles. Ensure ice and water protector has been installed along the valley first. Keeping all of the crowns pointing up prevents waves from marring the finished roof.

Shingle the addition roof letting the new shingles fold through the valley center and onto the old roof deck by at least 1 ft. The valley rafter is marked for a 12 in 17 pitch and then cut with a double bevel to fit into the ridge intersection. Up from the valley center. It is the upstands that prevent water from entering the roof space not the mortar.

Because most framing lumber is not perfectly straight i check each piece and mark the crown before i start cutting the lumber into rafters. Then starting at the base of the valley center your first piece of flashing in the valley. Make sure they are properly formed. To secure the roof valley flashing nail it down carefully.

Re lay the shingles you removed from the existing roof.