george wrote:
ive been having continual earache about the back patio basically it is
covered in some manmade substance which is impervious to brick acid
etc.so a relay is the only solution but thats where the problems
started when i tryed lifting the slabs it proved to be a back breaking
ordeal.seems like the patio slabs were layed in quite a layer of
mortar. (encased in concrete more like)
ive decided maybe to slab over it now but how far can i go to the
dampproof level of the house, looks like it would be within in an inch
of it and should i maybe slope it to help drainage!!

You could stick a simple ground level deck on it, thats what I did in the
same situation.
You don't have to use the massive joists they use in raised decks. I used
2"x3" joists.
Lot less back breaking work and quicker too.