You re better off removing the old roof.
Remove old roof or not.
For example if you live in an area that is subject to high winds keep in mind that shingles will hold better if fastened directly to the roof deck.
By placing shingles on top of a damaged roof you ll affect the way the roof looks.
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.
Clean the roof with a push broom and remove or pound in any remaining fasteners.
Not only will the existing layer provide a secondary back up roof for the new shingles but it will also save the cost and inconvenience of removing and disposing or recycling the old shingles.
But if the current roof is curling this isn t possible.
What to do if the old roof is not straight if the existing roof has wavy horizontal lines you can take out the waves by snapping a horizontal line 1 2 inch below the shingle bottoms of one course.
It s clearly easier and cheaper to leave the old shingles in place but there s some special prep work involved with a re roof removing vents ridge caps and misshapen shingles among other things and you still have to replace or add new flashing which sometimes can be tricky over old roofing.
Be careful not to damage the flashing.
Remove the old shingles with tear off shovels.
If you re keeping the old metal flashing carefully remove nails and bend it upward off the shingles with a pry bar.
Before making a final decision to tear off or recover check that local building codes are being followed.
Call for free estimates from roofing pros now.
In addition removing the old shingles will.
Although it sounds like a good idea we can assure you the cons heavily outweigh the pros.
Work from the top bottom and sides to save back muscles.
Putting a new roof over a leaking roof won t remove the leaks.
More difficult to check deck when you tear off the old roof you get a look at what s underneath.
It doesn t matter where you start or stop.
In fact the only pro to a shingle over is it s cheaper and cleaner.
Since it s being put on top of another less than perfect roof it s likely that it may not look as good as a brand new roof would.
Your roof leaks when it rains if your roof is leaking it s usually better to get rid of the old roof so you can find the source of the problems and fix them.
Skylight and chimney flashings are often worth saving if they re in good condition.
If you re going to add a roof on top of an old one it s a good idea to remove any loose shingles and apply a new layer of 30 pound roofing felt before laying the new shingles.
Find a pre screened local roofing contractor.
