Roof Valley Construction Details

Part 3 of the four part guide to roof construction covers pitched roof detail.

Roof valley construction details.

We describe how to construct three common styles of roof valley. Cad details document name pdf dwg download all cad construction details 37 1 mb 3 4 mb mc01 identification of roof areas 694 kb 167 kb mc01a single layer underlayment 678 kb 302 kb mc01b double layer underlayment 711 kb 322 kb mc02 vent pipe flashing 626 kb 349 kb mc03 valley. To get the most out of it is helpful to also read parts 1 and 2. Some grp valleys are sufficiently robust to enable them to be laid directly over the rafters rather than being supported on valley boards.

Part 1 a guide to roof construction covers an overview of flat and pitched roofs. There are two common methods for completing the flashing of a valley in a shingle roof system. Closed valleys or open valleys. One of the details that varies between homes is the method of flashing the valley areas of the roof.

These days cut ups or roofs with a lot of valleys dormers and other features are increasingly popular. Woven closed cut and open. In many cases with purchased house plans the details of the roof construction including rafter design are included. Open valley closed cut valley and woven roof valley and we include roof valley underlayment and nailing specifications.

Essentially there are three main ways to shingle a roof valley. This article discusses details and specifications for roof valley flashing for best construction roof leak resistance. Preformed grp valleys in many ways the roof construction for a pre formed grp valley is the same as that for a lead lined valley. To understand what makes a valley either closed or open it is important to understand how a valley is constructed.

It is therefore worth asking the valley manufacturer for guidance on this. Another common design in the northeast is the saltbox which is a gable roof with one longer side.