Add a new layer of shingles which means that there is no tearing off of the old roof.
How to shingle a new roof to an existing roof.
The bridging method allows the new course of roof shingles to overlay 2 or 3 courses of the existing roof shingles.
It is the process where roofers install a new roof over your existing one i e.
This method usually allows for the proper exposure of the roof shingles and is commonly used when applying metric sized roof shingles over english sized or over wood shingles.
Fold new shingles over the new valley onto the old roof overlapping by at least a foot.
The shingles should jut out from 1 4 to 3 8 inch 7 to 1 cm over the drip edge.
Why installing new shingles over old shingles can be good.
When you should tear off your roof and start from scratch instead.
Then nail shingles on the new roof and exposed areas of the old roof.
How to roof over existing shingles.
Many arizona homeowners with shingle roofs do decide to roof over their existing shingles because.
Installation is easier than for a tear off job because you can use the existing shingles as guides for laying the new ones.
When roofing over your existing shingles can be a good idea.
Each row should overlap the one below it by 1 4 inch 7 cm not less.
This is what it looks like when you install a steel shingle roof system over an existing asphalt shingle roof.
Let s start with the good.
The goal is to provide a reasonably flat surface for the new shingles to lie over with no gaps greater than 1 2 inch.
If the broken piece is lost cut a new piece to fit the existing shingle.
You can save.
Nail a horizontal row of shingles over the drip edge.
If conditions are right new shingles laid over old shingles can be just as attractive and durable as shingles laid on bare sheathing.
Finish your gable roof addition tie in by installing siding to match the existing house and fascia and trim boards at eaves and edges.
Installing a new roof over an existing one also called a layover or nailover is often possible although not always the best option a properly installed layover roof can look and function as well.
Venting the eaves to vent the roof holes are cut in the old roof above the soffit which pulls air through the soffit vents underneath.
Hammer the nail into the top part of each shingle.
If a shingle is torn or cracked glue the broken piece back in place using roofing cement.