Max@ableskills - Thanks
Scottley - Thanks, will do that
jay - Its an internal wall and there's no damp issues, so hopefully will be ok
devonmark - It wasnt really, £12 per 15kg tub, can live with that, someone somewhere through t'ebay will have it!
Dave - Thanks, they sure are!
Just incase it might be of use to anyone, I am a computer whizz, so any niggling problems you might have, might be able to repay some of the advice I'm getting on here!
So dot and dab, covering edges and top etc, having brushed loose stuff away, PVA'd surface before adhesive, mount p'board. Tape and tank. Wall done!
Stud wall, hopefully simpler, mount p'board, tape and tank.
Using flexible single part bagged for both these walls....
Onto walls 3 & 4!!!
Wall 3 has a large window in it, and the edge which meets wall 1 sort of fades away (about 1m width ceiling to about 2ft from floor) as such so it's a fair bit from straight. My thoughts were on that one, perhaps plaster over the bit which fades away to bring it level? Appreciate plaster tile weight not as good as p'board or render, but should be enough for the tiles I'm using, and it's not in a "wet area"? Or do you think chip the old render away and fill area with new stuff flush to whole wall better idea?