"Trevor Smith" wrote in message
...
Andrew,

well cob it aint then! It's granite blocks held together with some sort
of
brown muck, which the locals here refer to as "cob", to make up a 20"
thick
solid wall (no cavity). Thanks for web link on the tanking. The stuff our
builder was talking about is a type of cement based product that is
brushed
on underneath the final plaster skim. I think he said one of the products
was Vandex but I guess there are alternatives.

I know exactly what you mean (same area)

one of my walls was extremely damp due to
wooden wedges being left in the wall

I rendered over the granite, thinly and
roughly for grip, painted on a bitumen
coating, rendered & plastered to a finish