Flat asphalt roof dips/ponding between each joist - Torch on Felt?

[cc120]

Flat asphalt roof dips/ponding between each joist. Could I cover with Torch on Felt, or should I level the dips with some material so felting on level surface?

The flat roof covering could be felt I will upload a pic asap. But same question applies.

 

[foxhole]

Ply , osb used ? Too thin or water damaged , needs replacement .

 

[bobasd]

still waiting for pics?

 

[catlad]

Be careful stepping on those type of roofs because if its that chipboard stuff and its got damp it turn to weetabix with no structural capacity left. ie. death trap.