Can anyone offer me any advice on this building matter please?

[newts]

My joiner has said that he was called back to a renovation he did last year. The plumber found a leak on push fit connections going into the underfloor heating system( the expansion and contraction of the slab weakened the fitting. This wasn't part of the original works-so no blaming the plumber. He has said the water has damaged lots of the renovation work.

Estimated £12K to remove new bathroom, re-tile, replace stud walling bases plate(black mould) plasterboards-water has wicked up the boards, and re instate all fittings. I personally would never use plasterboard or green moisture resistant board in future. Either something like Knauf Aquapanel or Abacus Elements board. Totally water proof

Plasterboard is not a suitable substrate for tiling in wet areas like a shower enclosure(m/resistant is only marginally better). As you quite rightly suggest a tile backer board for wet areas is best, tanking coat over plasterboard a lowly second. Over 30 years I have replaced many bathrooms for customers with plasterboard failure being the root cause. Nowadays I regularly inspect new builds & plasterboard (now moisture resistant) is still the element that fails.

 

[Kingfisher101]

I think I've got it sorted now, I've got a plumber coming one day to take out the bath/toilet, the next day the joist/s and floor are getting done and the following day toilet back in and new bath. I'm having a go at tiling the floor myself, following on from previous tiling and decorating success.

 

[CXRAndy]

Have you seen these

https://www.wickes.co.uk/Vitrex-LASH-Tile-Levelling-Clips---Pack-of-100/p/210072

Make placing and leveling up tiles a doddle

My tiler used them, super quick

 

[neil_merseyside]

Have you seen these

https://www.wickes.co.uk/Vitrex-LASH-Tile-Levelling-Clips---Pack-of-100/p/210072

Make placing and leveling up tiles a doddle

My tiler used them, super quick

I tried them they are rubbish! Base clip was actually just so variable in moulding accuracy that they ranged from a few OK, to being tough to break (cleanly) and mostly too damn tough to break at all (without killing the tile!) and so most needed cutting off/back with a stanley knife.

 

[CXRAndy]

He must using better, because from I saw he had no problems removing the clips after tiling

 

[newts]

The Rubi Cyclone clips work very well & break off easily.