Re-tiling a shower room - remove or tile over?

[Profpointy]

There is some stainng on the low vertical grout lines that would indicate that there is some water ingress into the substrate, (mould growing in the porous plasterboard behind). Tile on tile is possible with correct prep & adhesives, personally I would not recommend it. Plasterboard is not a suitable substrate for tiling in a wet area (shower). I would strip back to the studwork, board the walls with tile backer board. Tape the joints & tank the walls. Prime with SBR (some adhesives may not require priming) then tile/grout.

Thanks, our plumber mentioned the grout staining suggesting it had been done wrong (like quite a lot in our house). Thanks to various advice here I think ripping the tiles off to check what's underneath, be it OK or shyte, is the best bet

 

[Kingfisher101]

Thanks, our plumber mentioned the grout staining suggesting it had been done wrong (like quite a lot in our house). Thanks to various advice here I think ripping the tiles off to check what's underneath, be it OK or shyte, is the best bet

Tradespeople always criticize the previous job that's been done. Its as mandatory as showing your arse crack whilst working. You can get rid of the grout staining by getting mould and mildew remover from Home Bargains etc.

 

[T4tomo]

Tradespeople always criticize the previous job that's been done. Its as mandatory as showing your arse crack whilst working. You can get rid of the grout staining by getting mould and mildew remover from Home Bargains etc.

can also be poured down a tradesman's arse crack....double win!

 

[Profpointy]

Decision made, and executed. Looks like it is the proper plasterboard with the green water resisted layer (and on the sides under the skim
coat), but the back board is trashed so I'll redo that anyway

Thanks everyone

 

[Profpointy]

And another little gem. Under the tiles, found this. For the avoidance of any doubt, this was not added by Mrs PP by way of encouragement after I'd chiseled all the tiles off

 

[slowmotion]

Decision made, and executed. Looks like it is the proper plasterboard with the green water resisted layer (and on the sides under the skim
coat), but the back board is trashed so I'll redo that anyway

Thanks everyone

View attachment 706411

One end of our shower is a timber frame partition. The builders used two layers of 12mm cementitious tile-backer boards before tiling, and it's worked well for the last 15 years. Unfortunately, they completely entombed the shower mixer valve so that the only way to service it has been to hack into the timber frame from the rear....otherwise it would have involved smashing up a few tiles and finding some matching replacements.

Is there no limit to the stupidity of these people? All they had to do was follow the valve manufacturer's instructions wnen they installed it.

Edit: the backer boards they used are Hardie TileBacker 500.

 

[CXRAndy]

I'm tiling at the moment, I used cement backer board, then tanked the shower area with Mapei tanking kit.

Our shower is surface mounted mixer version, art deco style.

It's such a long time since I tiled, but with these leveling wedges, makes for an easy way to keep all edges flush.

I run a laser levelled batten all around the bathroom for the first run of tiles, so I knew it wouldn't drift off alignment.

 

[Profpointy]

I'm tiling at the moment, I used cement backer board, then tanked the shower area with Mapei tanking kit.

Our shower is surface mounted mixer version, art deco style.

It's such a long time since I tiled, but with these leveling wedges, makes for an easy way to keep all edges flush.

I run a laser levelled batten all around the bathroom for the first run of tiles, so I knew it wouldn't drift off alignment.

If I hadn't been replacing an existing unit I too would have had the mixer thingy expose rather than tiled over.

 

[newts]

Most of the good quality concealed shower valves are fully sevicable from behind the faceplate. They have a plastic shroud slightly bigger than the valve bt smaller than the face plate. Some numpty often removes the first fix shroud & tiles up tight to the brass valve, then you can't replace the thermo cartridge or stop valve. Grohe make this modular concealed valve, many similar are available.

View: https://youtu.be/DHYkuCEr0i8?feature=shared

 

[Profpointy]

Job now totally jobbed. The tile guy replaced the worst of the boarding with the proper stuff, "tanked" the while lot with rubber goo, (which looked like a horrible job) and retiled and it looks great. The Mrs never liked the plain white tiles in any case, and I must admit it looks vastly nicer than before, the new shower works properly, and hopefully shouldn't leak. Perhaps even more optimistically damp on a nearby wall might clear up, though that could be wishfull thinking; we'll see

 

[CXRAndy]

"tanked" the while lot with rubber goo, (which looked like a horrible job)

Its really simple to do, just expect to throw your roller and brushes away afterwards. Glad it came out well, nice job

Have you got powerful ventilation with over run. I set mine for nearly 20 mins over run. This was enough time for the secondary extractor to drop down from high humidity detection

 

[Fastpedaller]

I'm late to the party, but will offer a tip in case it helps anyone else.
If tiles are onto plasterboard, just identify where the fixing screws are by using a powerful magnet. Take off only the tiles necessary to enable you to unscrew the plasterboard and take board complete with tiles to skip.
BTW any tiler worth his salt will not tile over existing tiles - OP made the correct decision of removing the tiles.