New Rafters Over Existing Roof

The roof sheathing on the old roof is not rotten just not up to the standards my dh thinks it should be.

New rafters over existing roof.

There s a lot of visible damage. Dh is a very skilled carpenter and is confident that he can do this work. Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option. We are planning to frame the new roof over the existing roof.

Some roofers install a layer of waterproof shingle underlayment wsu over the existing shingles at the eave end as would be done for a roof laid on bare sheathing. Use premade roof trusses premade roofing trusses will be easier and take less time than installing a stick built roof. Mold rot or other significant damage needs to be taken care of with a full replacement not hidden by new materials. However installing new flashings including special drip edge flashings made for reroofing will ensure a tight seal and a long life.

You need a flat surface to install a new roof over existing shingles. A properly installed layover roof can look and function as well. Premade trusses will form the skeleton of your new roof above your old roof. The cheapest option would be to leave the old roof in place and place the new rafters over the existing roof.

This provides added protection against ice dams. To make the blind valleys we attached sleepers to the shed roof locating them by placing a 14 foot straightedge that is usually used for screeding concrete on top of the porch rafters to project the plane of the new porch roof over to the surface of the existing shed roof. Place a length of 2 by 6 inch wood on the underside of the rafter ends so it bridges several of them and nail it to each one from below. We simply slid the straightedge over until it hit the shed roof and then positioned a 2 by under the straightedge and marked the edge of the 2 by.

Old shingles can curl over time.