How To Install Tin Roof Valley

Drip edge metal valley flashing dormer chimney and kickout flashing are types of roof flashing that shed water away from the connections between roofs walls chimneys and other building assemblies.

How to install tin roof valley.

Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles. Apply an approximately 3 inch width of asphalt roofing cement along the sides of flashing and embed shingles in mastic. Use tape sealant between the valley trim and the panel. These will stop the entry of rain wind and pests.

Place them directly onto purlins that are attached to the roof trusses beginning on the outside edge. Lay the flashing down in the roof valley and start at the lower end of the roof. Place the first screw about 7 inches from the bottom and each subsequent screw about 18 to 24 inches apart along the vertical run. First clean the debris out of the valley including sawdust nails and whatever else is in there.

Lay one and two tab shingles as you near the valley so full size shingles will run across the valley. The washer under the screw head should seal to the surface of the panel without bulging or shifting. With a clean valley you can lay down some peel and stick roofing membrane. Secure the screws but do not overtighten.

Install an underlayment centered in the roof valley. Roof one side of the valley running the shingles across it. 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. Use fasteners to attach the panel to the structure making sure that there is complete compression of the sealant.

Steep slope roofs slope greater than 3 12 cut the panels at an angle for the valley then bend the hem end of the panel and hook it with a cleat. Shingle the other side of the valley the same way. Use 1 inch galvanized roofing nails. Install synthetic roofing underlayment or felt paper according to manufacturer specifications and then install the first piece of valley flashing.

Stop nailing 6 inches from the center. Make sure that the end of the flashing panel is perfectly in line with the edge of the roof. Fold the top over the roof ridge and cut the bottom along the drip edge metal.