When is the best time to install solar tubes in relation to a new roof?
If your doing the work yourself its only your time you wasting but if your paying someone then its your money.  Flashing for solar tubes is not that bad just an oversized plumbing vent.  If your roof is in bad condition it could be a project because the shingles will break apart if they are too old a brittle. You May need to buy a bundle of shingles to replace the shingles you break.