Roofing Over Existing Shingles

Re roofers have tricks to lay new roof shingles over old so that the same step ups between courses are maintained but if any old shingles are cupped curled or otherwise misshapen those defects will telegraph through to the new layer.

Roofing over existing shingles.

Roofing over existing shingles on a roof with a 4 12 pitch can easily cost 1 000 less than tearing off and replacing an entire roof. The rest of the shingles are full width. 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. Roofing over an existing roof is also called reroofing or an overlay.

All shingle manufacturers honor the warranty whether their products are used for a reroof or a new roof. Let s start with the good. This can lead to increased rot mold and decrease the structural integrity of your home. If the job is done correctly with the new layer of shingles laid flat over the existing shingles the old roof cushions the new one and serves as a secondary barrier should wind or water ever break through the new shingles.

Many arizona homeowners with shingle roofs do decide to roof over their existing shingles because. Plus the hours of labor go down and less equipment is used which lowers the cost even more. The starter course or strip is rip cut so it butts up against the third courseof the existing shingles. Here is a video on how we lay a second layer of asphalt shingles over existing asphalt shingles.

It is the process where roofers install a new roof over your existing one i e. Leak around a dormer which the homeowner never knew about long term effects of shingling over shingles. Hope you like it. In a reroof job a special type of drip edge flashing is installed at the eaves and rake to wrap around the existing shingles.

When you should tear off your roof and start from scratch instead. In a shingle over if some of the decking has buckled and warped over the years it likely isn t going to be noticed and fixed. You can save money because there s no dump fee for removing your old roofing and there s no need for additional felt paper over the old roof. This provides added protection against ice dams.

Roof over shingle over has its place there are always factors to take into consideration before starting a project. However installing new flashings including special drip edge flashings made for reroofing will ensure a tight seal and a long life. When roofing over your existing shingles can be a good idea.