On Dec 31, 12:17 pm,
(D.M. Procida) wrote:

It would be convenient and cheap to put large plywood boards on a roof,
make sure that there's some kind of overlap or flexible seal where their
edges meet, and finish them with thoroughly waterproof paint.

The last two houses that I have seen built around here have a plywood
roof covered in copper sheet or copper tiles. They should not need
painting.