I am looking to have my flat roof refelted, the tradesman used by a neighbour has felted over existing felt. Is this acceptable/recommended at all?

never.. always take old felt of expose the marine ply to check for any water damage etc.then place slaters felt followed by an underlay then a mineral felt over the lot. you shouldnt take any chances when it comes to roofs and flat roofs.

No its not acceptable, the existing felt should be stripped of first, then check the roof deck is sound before refelting. Hes covering up bad felt and you wont get a gaurantee.

hi if the existing flat roof boards were ok and the roofer got a clean base to work on then i have seen it done before,personally i would have removed the existing felt to check for any damage to boards

depends on what she was willing to pay ,its not the correct procedure ,that would be to strip off back to board ,checking that board is solid if not replace then 3 layer felt system back ,but as always the correct procedure is more expensive ans she may have been willing to settle for botch job