How To Install Tin Roof Valley

Install the roofing screws vertically along each rib in the panel.

How to install tin roof valley.

Use 1 inch galvanized roofing nails. These will stop the entry of rain wind and pests. Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles. Fold the top over the roof ridge and cut the bottom along the drip edge metal.

Make sure that the end of the flashing panel is perfectly in line with the edge of the roof. Roof one side of the valley running the shingles across it. Use fasteners to attach the panel to the structure making sure that there is complete compression of the sealant. Close or seal off the ends with a wood or plastic strip under the panel at each end.

The washer under the screw head should seal to the surface of the panel without bulging or shifting. Place the first screw about 7 inches from the bottom and each subsequent screw about 18 to 24 inches apart along the vertical run. With a clean valley you can lay down some peel and stick roofing membrane. Lay the flashing down in the roof valley and start at the lower end of the roof.

Place them directly onto purlins that are attached to the roof trusses beginning on the outside edge. Shingle the other side of the valley the same way. 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. Lay one and two tab shingles as you near the valley so full size shingles will run across the valley.

Secure the screws but do not overtighten. Attach the flashing panel in place at the bottom. First clean the debris out of the valley including sawdust nails and whatever else is in there. Apply an approximately 3 inch width of asphalt roofing cement along the sides of flashing and embed shingles in mastic.

Install synthetic roofing underlayment or felt paper according to manufacturer specifications and then install the first piece of valley flashing. Use tape sealant between the valley trim and the panel. Install an underlayment centered in the roof valley.