Fitting bathroom units/tiles before or after skim coat

[macadonald]

Hi guys,

I have the plasterer in at the moment and am planning to fit the new bathroom in the next couple of weeks. The walls are back to brick and he is doing the wet sand cement render and then multifinish through the rest of the house. Am I okay to ask him to only apply the wet coat render in the bathroom for now? Can I tile straight onto this? I would have thought this would be a better grip than tiling on to smooth skim, which would only be covered by tiles and units anyway. Is it okay to fit the cupboard units so that it will only be the render behind them and again I will tile above these.

On the wall that I plan to tile half way, I thought it would be best if I tiled all but my last line of tiles and then ask the plasterer to multifinish the top tapering it thin to just below the top of the last tile line.

He seemed happy with this, but then he seems happy with anything? But would really appreciate your advice, as I'm going to fit the bathroom myself. Really just concerned about whether the render (without skim) is okay behind the units and behind tiles?

Thanks

 

[Richard C]

Ideally you should not plaster if tiling, it’s not necessary & reduces maximum permissible tile weight to 20 kg/sqm, including up to 4kg/sqm for the addy & grout; this can be a problem if your proposing to use heavy large format tiles! Get your spread to leave you a flat render finish which will take around 45 kg/sqm & tile onto that but you must leave it to dry out thoroughly before tiling or you will have problems; around 4 weeks for a base coat & skim. If time is an issue, you need to use a quickset render (expensive); another method it to fix waterproof tile backer boards & tile straight onto that but check the backer board will accept a skim; most will if prepped correctly even if the manufacturer says no. Fix tiles larger than around 250mm with powder adhesive rather than tub mix; it’s OK to use this on render but any Gypsum plaster must be primed to avoid a reaction with the cement in the addy.

Your spot on with your method of half tiling; I mark the top of the tile line on the wall & waste the skim into the area just below the line; tile over when the skim is dry (around 10 days). I wouldn’t normally tile around bathroom units, it can look a bit naff, how many & where are they?

Do your homework before tiling, read the Tiling Forum sticky & archive posts to avoid ,aking basic & potentially expensive mistakes.

 

[macadonald]

Richard,

Very useful response, thanks a lot.

Regarding the units and tiling around them, what do you suggest then? This is a single unit on one wall only. It's one of those that incorporates the toilet, and basin with a cupboard below the basin? I would certainly need some form of splash back tiles that also go up into the window sill. Are you referring to the wall tiles? Do you suggest tiling first and then placing the unit and simply using silicon to create the joins?

 

[Richard C]

I had assumed you meant the wall tiles; I would normally tile first & then fit any units & sanitary ware but you should at least tile behind the outline of the unit even if you don’t fully tile behind. Silicone around the units & sanitary ware to provide a seal after fixing in place; clear or white depending on tile colour & what effect you want

With floor tiles, you should always fully tile the floor (except under the bath if you cant see it) & then fit out but if your tiling onto a suspended timber floor, it needs special consideration & prep so I would again advise you read the Tiling Sticky & Forum archives; get it wrong & it won’t last.