Tiling onto fresh plaster: disaster or not?

[drmrbrewer]

Am about to start painting our new bathroom, which has been freshly plastered all over (now dry). I'm starting with a mist coat, and am just wondering whether I should put the mist coat all over, even in a corner where we will be installing a shower, with tiles in that area.

I've been trying to research whether I should leave the plaster bare for the tiler, or whether at least to put down a mist coat in order to seal it a bit. We'll be putting on 250x400mm tiles, nothing too chunky.

But I'm thoroughly confused. Some suggest that fresh plaster is a disaster for tile adhesive (too absorbent), and recommend a mist coat or even special seal coat (even PVA). Others say that it's best to tile directly onto the plaster, because a layer of paint is not the best medium to hold tiles up. The plasterer suggested I don't apply paint, but he's a plasterer and not a tiler.

A mist coat doesn't really add a layer, it mainly soaks in. So I'm thinking that at least a single mist coat would be sensible.

But, as I say, I'm thoroughly confused by the mixed messages. Any advice appreciated...

 

[joe-90]

Better off with an acrylic sealant. Don't tile on bare plaster, it won't grip.

 

[drmrbrewer]

An acrylic sealant like what?

 

[foxhole]

http://www.screwfix.com/p/mapei-shower-waterproofing-kit/78484

 

[drmrbrewer]

Sorry for being thick, but aren't tiles waterproof already... what is the need for an expensive waterproofing layer underneath? I appreciate that grouting will fail/leak over time, but a waterproof layer will just cause the leaks to track down onto the floor/ceiling below?

 

[joe-90]

Yes I agree. I should have said 'Plaster primer'. http://www.screwfix.com/p/mapei-pla...d-MIQ47ERxfMvu1HueJVkGDyRaR3QPnuNQaAoYJ8P8HAQ