The concept of a non-fragile roof might make walkovers seem unnecessary, particularly on a roof that has been given an A-rating.
But an article circulated in the trade press by Chris Pearce, a founder member of the Advisory Committee for Roofsafety, explains why even a good rating does not mean a roof is totally safe.
He explains how non-fragile ratings are determined – by dropping a sandbag on to the roof assembly, to simulate a workman tripping and falling while working on the roof.
If the roof withstands the force once, it receives a C-rating; twice and it is awarded a B-rating; and if no damage is detected after two drops, an A-rating is awarded.
But this only applies to the total roof assembly when installed exactly in line with the manufacturer’s specifications, with the correct type and number of fixings, and so on.
“These controls reduce the risk of poor workmanship but realistically cannot alone guarantee that the assembly is safe to walk on, unless there is clear evidence to establish that it is safe,” writes Mr Pearce.
For this reason, walkovers remain an important addition to any rooftop where access is required, to ensure the fragility of the roof itself does not lead to an incident occurring.