Any one out there that can give me some good advice please. My house is about twelve years old and the internal walls on the first floor are made up of egg-box like plasterboard. The builders had tiled the en-suite directly onto the plasterboard and I had to change it last year because of a leak. I replaced the old board with new, tiled it with good quality products and fitted a new cubicle that sits on a 1100 x 800 solid ceramic/resin base. I've just found that that the unit is leaking where the cubicle and tray meets the wall, probably in the corners. Obviously the tiler has not used enough sealant.Consequently the plasterboard has failed right around the first row of tiles. I've stripped out the wet plasterboard and tiles to let the timber dry out - I don't want to knock the tiles off and start from scratch with aqua-panel, so I was wondering if it's possible to replace the old plasterboard with aqua-panel up to the dry plasterboard, seal the joints with tape and waterproof tile adhesive and re-tile over that. If so, my concern then is that as the aqua-panel is porous, if this happens again I can't afford for the timber frame to become comprised so I want to protect that. Finally, any tips on the best shower trim to use between the tiles and the tray - I would prefer a one piece strip rather than using two sections. Any pro advice greatly received. Thanks