Depends on the shape of the conservatory and what the roof is made of.
With mine, it's lean-to at the back of the house, with a polycarbonate
roof. I have in the past used crawling boards to distribute the weight
of people & things on the conservatory roof, while working above it.

Not sure what shape you'd describe it as - it protrudes from the back
of the house by about 8 feet, and has a corner lopped off for the
doors to the rear.

If the poly's old, it might have gone brittle, but if so then it probably
needs changing as part of the work.

Not sure of the age, it was a repossession :-}