Roof Valley Against Wall

Ideally i like to start by installing a 3 ft.

Roof valley against wall.

One layer each of felt underlayment mineral surfaced roll roofing and two layers of shingles. Valleys are typically found where gable dormer roofs meet the main roof or when a house has angled wings or additions where two roof sections in different planes meet. The sheet acts as a backup at a vulnerable junction. Proper roof wall abutment flashing examples.

It is commonly used in two story and side split houses. Metal roof flashing is a galvanized sheet metal bent at right angles with about eight to 12 inches on each side of the angle. Sheet of housewrap or even better a piece of self adhering roof underlayment to the wall before the first truss or roof rafter is placed against it. If you don t direct water from the roof into a gutter it can pour into the wall.

Install an underlayment centered in the roof valley. Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles. A roof valley is formed where two roof slopes meet. The flat roofing material must go up the wall a minimum of 12 or up the wall and over the top of the wall if the wall is less than 12 high.

Your choice of valley installation method is critical because when improperly installed valleys are risks for serious leaks. Metal roof flashing can be use to seal gaps between roof walls. Below are two photographs of roof wall step flashing completed and effective of a slate roof against a brick wall below left and in process with step flashing against a dormer sidewall before the dormer siding has been put in place below right. Housewrap creates the foundation.

A closed cut roof valley will have at least four layers of roof materials. Woven closed cut and open. Then install a non corrosive metal valley flashing of 24 minimum width lap successive sheets of metal flashing a minimum of 12 inches and seal laps. These kinds of houses often have a roof that butts against a wall.

Water collects in a valley to flow off the roof. Here is an attempt though maybe not a very good one to make the roof flashing serve also as a through the wall flashing with a tile roof. Lay one and two tab shingles as you near the valley so full size shingles will run across the valley. Stop nailing 6 inches from the center.

Roof one side of the valley running the shingles across it. Ground zero for roof rot is often where roofs meet walls. Closed cut shingle valleys work fine with strip shingles and laminated asphalt shingles. Avoiding problems begins at the beginning with a gap.

Essentially there are three main ways to shingle a roof valley.