How To Install Roof Shingles Over Existing Shingles

Cut the existing shingles and pry up carefully.

How to install roof shingles over existing shingles.

The uncut shingle should hang a quarter of an inch over the roof edge. Mark the location of the top of the uncut shingle on the felt. Along the rakes install a new j channel drip edge which wraps around the old rake flashing and starter courses. Position one of the uncut shingles on top of a trimmed shingle.

Installing new roof shingles over old effectively doubles the weight of the. Good quality composite shingles can weigh 350 to 450 pounds per square 100 square feet of roofing installed. Install new shingles to the lower edge of the opening. Leave the old valley flashing in place and install new over it.

Looks just as good and lasts as long. Around an inch should do. 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. Attach with nails along the top edge of the strip.

Use a starter strip or cut pieces for a starter course. 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. Chances are your roof structure was designed for a dead load of one layer of shingles plus extra for snow and a safety margin. Has the same manufacturer s warranty.

How to shingle over existing shingles and how to shingle a roof how to install roof shingles shingle layout lines h. Manufacturers will still. If you nick or tear the old flashing piece then go buy a new one. To level out an existing asphalt shingle roof rip down reduce the height of two.

The first row of shingles should overhang the drip edge of the roof. Use the chalk line to mark the line at that spot across the 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. Roofing second layer of shingles roofing.

Each shingle will require around 4 nails underneath the tar line and about half an inch under where the next shingle will overlap. Along the eaves install a new drip edge over the butt ends of existing shingles. Continue marking lines every five inches up to the roof ridge. Installing a new roof over shingles takes less time than tearing off the old roof.

This provides added protection against ice dams.