How To Metal Valley Into Existing Roof Line

Because most framing lumber is not perfectly straight i check each piece and mark the crown before i start cutting the lumber into rafters.

How to metal valley into existing roof line. Apply an approximately 3 inch width of asphalt roofing cement along the sides of flashing and embed shingles in mastic. Install an underlayment centered in the roof valley. Shingle the addition roof letting the new shingles fold through the valley center and onto the old roof deck by at least 1 ft. Re lay the shingles you removed from the existing roof.

Remove siding from the house where the new roof will attach to expose rafters or other framing of the old 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. 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.

Best practices for sealing the metal roof valley vary based on the slope of the roof. 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. Lift the underlayment out of the way and then lay a 3 ft wide roll of waterproof shingle underlayment in the valley. Soup to nuts riley shows the proper way of installing a valley on a roof.