When putting a second layer of shingles on a roof will i have to worry about hitting the nails below?

thanks wired for the useful info. before.When putting a second layer of shingles on a roof will i have to worry about hitting the nails below?
You won't need to worry about it. Occasionally you'll hit one and you'll need to move over a fraction of an inch.When putting a second layer of shingles on a roof will i have to worry about hitting the nails below?
If you start your new shingles a little lower than the old ones you should have no problems.
I would recommend a complete tear off of old roof so that you can inspect for bad wood and to install ice %26amp; water shield at all eves %26amp; valleys to insure you do not have ice damming in the future (If you live in a area that gets a lot of snow.)%26amp; another good reason for this is sometimes nails in the older shingles work their way up %26amp; can cause damage to your new roof. Also the more layers of shingles you add is just more weight added to your roof.
As a roofing contractor I don't recommend doing a second layer all your doing is covering up problems down the road but if your looking for a cheaper way I would recommend a Tamko dimensional their made to but and run right the 3 tab shingle you can get them at most roofing store home depot or Lowe's would have to order them
I strongly advise you to pull that first roof off.





Placing a new layer of shingles over the current ones is no assurance that you'll stop any leaks.





The felt under the current shingles is at least as old as the shingles, and any walking on the roof on top of nailing down a new layer will just increase the odds that you'll be doing this shortly.





Bite the bullet and do the job correctly. You'll be much happier with the results.