Does a roof terrace have to be tested for its weight bearing capacity?

Does a roof terrace have to be tested for its weight bearing capacity?

Lisa Andrews (Horticulturalist) gives expert video advice on: Do I need an architect to design a roof terrace?; Do I need a structural engineer for a roof terrace?; Should I hire a specialist roof terrace constructor? and more...

The structural engineer will make his own calculations depending on the size of the ceiling joists below and decide whether to use the steel and timber joists to construct an entirely new roof surface.