Old Roof New Roof Joined Rafters

Remove shingles and other roofing material where the new roof will join down to the deck board of the old roof.

Old roof new roof joined rafters.

You can strip the shingles out of the area that the new roof will cover but to be safe i often leave the old shingles in place and frame over them. A new level 2 6 ridgeboard and rafters then are assembled over the old roof and are attached to the existing structure with nails and lag screws driven into the underlying wall top plates. A properly installed layover roof can look and function as well. They form an upside down v with the point at the top of the addition roof.

Put siding on the new roof end replacing any removed from the old roof area. Install bent metal flashing where the old and new roofs meet and on the peaks and metal drip edges along the eaves. Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option. You ll need to install a valley board or nailer over the old roof shingles to create a solid nailing surface for installing jack rafters see drawing.

Nail oriented strand board osb decking over all the new rafters.