Rising damp doesn't exist.

So all those damp proof courses are basically ******** then?

Largely yes, although some types of damp proof course will help against
penetrating damp caused by piled up soil, or rain bouncing off hard
surfaces.

It is possible to replicate some sort of rising damp in a laboratory and
occasionally even in practice. However, almost all diagnoses of "rising
damp" in reality are pure fiction and are, in fact, misdiagnosed penetrating
damp or condensation.

Christian.