how can i fix a hole in my conservatory roof?

Either replace the acrylic sheet or over lay and mastic or glue a patch of plastic over the split if it seems as though the edges have melted then my guess is a firework landed still alight. I understand your meaning flat sloping meaning shallow sloped roof. The other alternative to damage is tiles/slate damage from the main roof. Check with your house insurance you may be covered for repairs it's worth a try.

Bob
June 2010