Can shingles be reused

After having new Tar paper and new shingles installed on the roof, the shingles looked terrible. As a result, the builder is currently redoing the roof, but there are some concerns.

After removing the new shingles, they are using the same Tar paper and using most of the same shingles. Could doing this be a potential problem? Is putting a new set of holes in the shingles and Tar paper going to be a problem or is it irrelevant due to the shingles overlapping?

 

Using the same tar paper (felt) is not uncommon. He should refelt any areas in which the felt has torn.
I guess in theory, using the same shingles would be acceptable, however, I can't imagine the painstaking process of removing an entire roof without damaging the shingles!?
If the shingles are torn or damaged in any way, they should not be reused. If they're in good condition (again, in theory) they can be reused, but I don't believe it's good practice to do so.
For one, it would be cheaper, labor-wise, to quickly tear off the existing roof and buy new shingles as opposed to gently and very time consumingly unfastening each individual shingle without tearing them. Not to mention laying them neatly and flat so that they will be ready to be reapplied. If it's hot out, they will stick together in a stack if not properly placed.

I know some on here will say that they should NEVER use shingles over again, and I would agree. However, whereas I would never, ever do it, ...... in theory, it can be done. Repairs are done this way when shingles are taken out and replaced.

The risk? Extra nail holes in felt and/or shingles without being covered with plastic cement is never preferred.

Reusing the felt? Not the prefered way, but acceptable.
Reusing the shingles? Not good practice.

Good luck

 

I agree with Nomad. However, I feel that there is more to this problem then you have told us. There is some reason the roofer is using the shingles he took off. Very time consuming work.