Preparation for Tiling - Walls

[mr_bus]

Hi. My daughter is having a walk in shower fitted by builders. I am concerned because most of the forums I have visited seem to advise the use of cement board in the wet area although I admit there does seem to be some disagreement about this. The builders have used concrete board on one of the walls (third pic down), but mostly to firm up the wall prior to tiling as it has a pocket door and was a bit flexy prior to the concrete board. However, on the other walls they have used GTEC moisture board. GTEC website does not give much advice on this board but Knauf site specifically states on their moisture board information that 'if tiling in a wet area, use Knauf AQUAPANEL' Moisture Panel | Moisture Resistant Plasterboard - https://www.knauf.co.uk/store/moisture-panel/c-23/p-58. I have mentioned this to the builders but they assure me 'they've done this loads of times'.

I have done plenty of bathrooms and kitchen and to be honest always err on the side of caution with any decision on materials even if it does cost a little extra. I would be grateful if someone could take a quick look at the pitures provided and hopefully reassure me that all is ok, or, if I need to have a frank discussion with the builders.

Forgot to say - they are not planning on tanking, just tiles straight on top of board.

Thanks in advance.

 

[Notts_Rob_66]

They should be using a backer-board - a lightweight multiboard with foam core works well - with joints sealed, or tanking the board that’s been put in place (not needed if right board used in the first place. See BS 5385, standards for tiling, which recommends waterproof board In bathrooms.

 

[mr_bus]

They should be using a backer-board - a lightweight multiboard with foam core works well - with joints sealed, or tanking the board that’s been put in place (not needed if right board used in the first place. See BS 5385, standards for tiling, which recommends waterproof board In bathrooms.

Hi Notts Rob. Really appreciate your taking time to reply. I didn't realise there was a British Standard for tiling. Tried to find an except from it but seems like it's something one has to purchase. In any case they went ahead with tiling on moisture resistant plasterboard, but they did tape up the joins with a yellow/green tape, not sure quite what. Keeping fingers crossed now. No siliconed expansion joints at corners even though I specified this - bit of a concern there too. The shower is part of a garage/annexe conversion. Trouble is I think the the builders we have are jack-of-all-trade. They just crack on with what they think is ok regardless of what is suggested/specified. I had to inform the 'plumbers' that the box on the wall was a digital shower control unit not an electric heating unit - lol! Hey ho, gonna bite my tongue and hopefully the building won't collapse.

 

[Notts_Rob66]

Hi Notts Rob. Really appreciate your taking time to reply. I didn't realise there was a British Standard for tiling. Tried to find an except from it but seems like it's something one has to purchase. In any case they went ahead with tiling on moisture resistant plasterboard, but they did tape up the joins with a yellow/green tape, not sure quite what. Keeping fingers crossed now. No siliconed expansion joints at corners even though I specified this - bit of a concern there too. The shower is part of a garage/annexe conversion. Trouble is I think the the builders we have are jack-of-all-trade. They just crack on with what they think is ok regardless of what is suggested/specified. I had to inform the 'plumbers' that the box on the wall was a digital shower control unit not an electric heating unit - lol! Hey ho, gonna bite my tongue and hopefully the building won't collapse.

I hope that it goes well. Here’s a useful link https://www.tiles.org.uk/wp-content/uploads/2020/04/Tiling-Guide-Download.pdf