[Chat] roof maintenance

[Joshua Fruhlinger]

Hi Charles Villagers!  I am guessing that most of us have flat rowhouse roofs of similar types and vintage.  I am wondering if anyone has any advice on (a) how often these roofs need to be resealed, (b) what roofing companies you have hired for said purpose who you've had good experiences with, and (c) what a typical price is to have it done.  Thanks in advance!

Josh