How To Metal Valley Into Existing Roof Line

Best practices for sealing the metal roof valley vary based on the slope of the roof.

How to metal valley into existing roof line.

Use fasteners to attach the panel to the structure making sure that there is complete compression of the sealant. Connect a flat roof to a sloped or pitched roof with a ledger board. Remove siding from the house where the new roof will attach to expose rafters or other framing of the old 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.

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. Keeping all of the crowns pointing up prevents waves from marring the finished roof. The valley rafter is marked for a 12 in 17 pitch and then cut with a double bevel to fit into the ridge intersection. Because most framing lumber is not perfectly straight i check each piece and mark the crown before i start cutting the lumber into rafters.

Soup to nuts riley shows the proper way of installing a valley on a roof. Soup to nuts riley shows the proper way of installing a valley on a roof. Re lay the shingles you removed from the existing roof. Apply an approximately 3 inch width of asphalt roofing cement along the sides of flashing and embed shingles in mastic.