New Rafters Over Existing Roof

Old shingles can curl over time.

New rafters over existing roof.

This provides added protection against ice dams. 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. The roof sheathing on the old roof is not rotten just not up to the standards my dh thinks it should be. Premade trusses will form the skeleton of your new roof above your old roof.

How to tie a additions roof to existing roof roof additions to existing roofs how to construct a roof from an exsisting shead how to change a roof line how to attach a deck roof to existing roof how to add a roof over porch attache porch roof on house attach shed roof to house adding a roof to screened in porch adding a roof to existing. 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. Mold rot or other significant damage needs to be taken care of with a full replacement not hidden by new materials.

The cheapest option would be to leave the old roof in place and place the new rafters over the existing roof. A properly installed layover roof can look and function as well. 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. 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 aren t planning on going up a floor so the roof would only be marginally higher than it is now. 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. We are planning to frame the new roof over the existing roof.

To increase the strength of your new and existing rafters and to help eliminate the chances of sideways movement consider installing a support board across the rafter endings on both sides of the roof.