The old roof had been leaking for some time which had rotted out the edges of the floor which we had replace the previous summer. We were not sure how sound the supporting structure was so we were very cautious getting up on it until we had established it was still strong. We were fortunate to have volunteer helper Mike staying with us at the time who had done this sort of thing before. We were also incredibly lucky with the weather as all the old bitumen roof sheets had to come off at once. Some of the under ply needed patching before the new box profile sheets were put on. This was made much easier as the local roofing company we used had made them to the exact length needed.