Installing New Roof Over Existing One
You need a flat surface to install a new roof over existing shingles.
Installing new roof over existing one. The cheapest option would be to leave the old roof in place and place the new rafters over the existing roof. It is not possible to mix materials nor to install a new layer over slate or wood tiles. Beveled wood pieces called horsefeathers must be laid along the thick edges of the shakes to make a fairly flat surface. Mold rot or other significant damage needs to be taken care of with a full replacement not hidden by new materials.
Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option. Use premade roof trusses premade roofing trusses will be easier and take less time than installing a stick built roof. As long as it s done right and under the right conditions installing new shingles over old ones can last as long and look just as good as a complete re roof. Has the same manufacturer s warranty.
Looks just as good and lasts as long. A properly installed layover roof can look and function as well. Manufacturers will still warranty the roof for the same amount of time as a re roof as long as it s done by a qualified installer. There s a lot of visible damage.
Installing a new roof over shingles takes less time than tearing off the old roof. Old shingles can curl over time. Asphalt shingles can be laid over cedar shakes or shingles however this is a roofing project best left to pros. The installation of metal roofing is often easier and faster than other roof types and because of its simple design and generally large size can actually be installed directly on top of existing roofing materials like asphalt shingles and foam roofing.
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. Before you reshingle a roof read our step.