Although it sounds like a good idea we can assure you the cons heavily outweigh the pros.
New roof over existing shingles.
But you must take care to install the shingles correctly so they lie flat.
Remove the ridge caps.
If a shingle is.
Let s start with the good.
When roofing over your existing shingles can be a good idea.
Mold rot or other significant damage needs to be taken care of with a full replacement not hidden by new materials.
Remove air vents and pipe flashings by prying out or unscrewing the fasteners holding the fixture.
The felt should be secured every six inches with nails or staples.
How to do it remove caps.
Old shingles can curl over time.
Doing it now will make it easier to keep the reroofing job clean.
The layers of felt should be overlapped by 1 inch as you work toward the roof ridge.
Installing new roof shingles over old effectively doubles the weight of the roofing so you have to make sure your roof structure can handle the extra load.
In fact the only pro to a shingle over is it s cheaper and cleaner.
Many arizona homeowners with shingle roofs do decide to roof over their existing shingles because.
The roof should be in sound.
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.
The condition of the existing roof is critical.
When contemplating a new roof many people hope to simply do a shingle over and avoid the extra cost and mess of tearing off the existing roof and starting from scratch.
That s also why building codes commonly limit re roofing to no more than two layers.
Yes you can install a metal roof over shingles.
Use a flat pry bar.
Reroofing is the process of layering one set of new shingles over a set of existing shingles.
There s a lot of visible damage.
Because there is no tear off reroofing can go much faster and be much less expensive than a complete roof replacement.
Multiple layers of shingles can make it difficult or impossible for the nails to penetrate.
Installation is easier than for a tear off job because you can use the existing shingles as guides for laying the new ones.
Building officials in some areas will only allow a re roof over one layer of shingles while officials in other places may allow you to place the roof over two layers of shingles.
Inspect the condition of your current roof.
This will help keep any moisture from getting under the felt.
If conditions are right new shingles laid over old shingles can be just as attractive and durable as shingles laid on bare sheathing.
It can only be done once so if you already have two layers of roofing in place reroofing is not an option for you.
When you should tear off your roof and start from scratch instead.
You need a flat surface to install a new roof over existing shingles.
However you ll want to check with your local building department before you make any decisions.