Suggestions for avoiding moulding on grout for mosaics

[u587162]

I will be tiling a 1600mm wet room seat most probably with a mosaic style tiling for my steam room. Im worried about the fact that water or steam might just sit on the grout despite it having a slight slope, there will be some damp on there.

Will this go mouldy after a bit? Some tile shops are proposing epoxy grout, is that any better?

 

[opps]

I have only used epoxy a couple of times. Great stuff but a pig to work with. It takes a lot of polishing to remove all traces from the tile surface. I would recommend it for your seat.

 

[u587162]

Thanks, what is epoxy exactly and how does it differ from grout / what's the benefit?

 

[opps]

I have only ever used the Mapei epoxy grout (Kerapoxy). They sell dozens of colours and matching silicones.

It is about £20 for a 2Kg tub.

https://www.sealantsandtools.co.uk/grouts/mapei-kerapoxy-epoxy-grout

You buy it by the tub. In the top of the tub is a small bottle of catalyst. You pour the catalyst in to the tub and mix it with the "paste". The catalyst generates heat to cure the grout. In many respects it is similar to 2 pack filler but has a longer working window and is thinner.

I last used it on my glass mosaic hob splashback. I didn't want to use regular grey grout because of cooking stains. The epoxy was resistant to things like oil and ketchup. I regularly cleaned the tiles with scotch pads and at no point did the grout ever discolour.

The only downsides were cost and longer application times. It takes a lot of wiping to ensure you don't leave any residue on the tile surface.

 

[u587162]

What about prevention of mould and mildew?

 

[opps]

TBH, I have never used it in a steam room.

I would expect it to be as problematic as mould on the tile face (that is to say it wipes off)

See

https://www.homerepairtutor.com/epoxy-grout/