Paul wrote:
My parents are convinced that they need to sign away several
thousands
of pounds on a treatment known as Protectacoat for a house which
has
solid brick walls with pebbledashed render - this is at least 50-60
years old and now there is some penetrating damp.

It is my understanding that solid walls have to 'breath'. Do you know
a reputable painter and decorator?,one should be able to give you the
correct advice after seeing the walls.