How To Install Roof Shingles Over Existing Shingles

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.

How to install roof shingles over existing shingles. Roofing second layer of shingles roofing. This provides added protection against ice dams. If you nick or tear the old flashing piece then go buy a new one. Each shingle will require around 4 nails underneath the tar line and about half an inch under where the next shingle will overlap.

Installing new roof shingles over old effectively doubles the weight of the. Chances are your roof structure was designed for a dead load of one layer of shingles plus extra for snow and a safety margin. The first row of shingles should overhang the drip edge of the roof. Manufacturers will still.

Remove the cover and then nail the old shingles back down again. However installing new flashings including special drip edge flashings made for reroofing will ensure a tight seal and a long life. Rip cut the starter strip or starter pieces so that they butt up against the second course of existing shingles and are even with the front edge of the existing roofing. Leave the old valley flashing in place and install new over it.

Has the same manufacturer s warranty. Looks just as good and lasts as long. Attach with nails along the top edge of the strip. Along the rakes install a new j channel drip edge which wraps around the old rake flashing and starter courses.

Mark the location of the top of the uncut shingle on the felt. Installing a new roof over shingles takes less time than tearing off the old roof. Use the chalk line to mark the line at that spot across the roof. Use a starter strip or cut pieces for a starter course.

How to shingle over existing shingles and how to shingle a roof how to install roof shingles shingle layout lines h. Do both sides first and then install ridge cap shingles over the top. Continue marking lines every five inches up to the roof ridge. To level out an existing asphalt shingle roof rip down reduce the height of two.

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. Cut the existing shingles and pry up carefully. Good quality composite shingles can weigh 350 to 450 pounds per square 100 square feet of roofing installed. Along the eaves install a new drip edge over the butt ends of existing shingles.

The uncut shingle should hang a quarter of an inch over the roof edge.