plaster in shower

[chookchook]

please help! I don't know whether this should be in plaster or building or plumbing! We have a shower which was leaking, so I was going to regrout and reseal, but noticed some of the tiles were loose, so I removed them (they kind of dropped off!) and behind it looked like thin plaster on insulating board (our house is entirely stud wall on metal frame as it's a listed building conversion). The plaster was all soft as it had got so wet and it fell away, it took a small part of the insulation board with it. Now I don't know how to repair so I can retile. Or do you think this is a complete 'rip out as start again job? The other two walls in shower were some kind of plywood with tiles on top, don't know if any of you guys have experience in this too? The plywood has gone black from it also getting wet before we found the leak!

http://i1348.photobucket.com/albums/p726/sandcraybould/th_IMG_2273_zps8cf6d55e.jpg

http://i1348.photobucket.com/albums/p726/sandcraybould/bth_IMG_2274_zps9c98ea83.jpg

 

[roughcaster]

I'd bite the bullet, rip it all out and start again. Don't use plasterboard though, use a cement based Hardie Backer boards. Much stronger than plasterboard and also water resistant. They're designed for tiling in showers and wetrooms. Another thing,,, having a cutting along the bottom of a shower is not a good idea, better with a whole tile, and make sure there's a good bead of silicone around the tray, better still, do it twice. Fit the tray then silicone,,, fix the tiles, then silicone again. When putting silicone around a bath, fill the bath with water first to add weight, then silicone, and leave the water in the bath for a few hours, until the silicone has cured. Keep an eye on small kids as well, while the bath has water in it for a prolonged period of time.