Hello can you recommend a waterproof tiling grout suitable for the sustained wetness of a wetroom floor. I've just bought a waterproof Unibond powder which I thought was suitable until I read the back of the packet where it states 'not suitable for sites of continuous immersion'. Thanks.

As you're not relying on the adhesive and grout to create the water barrier, you don't need "waterproof", you just need a cement based grout. Though still check to make sure it's fine with continuous immersion. The waterproof barrier should be some form of tanking system that you're tiling onto, therefore something like a cement-based adhesive and grout will allow the water to pass through it and dry out when it's not being used, though wont break or fail in any way.

I'm not a tiler though, so I guess you'll get some more responses with more detail.

Thanks for the response Dan. I've installed a tanking system etc., but I would rather have a completely waterproof grout if at all possible. I've bought some 'flexi-mix additive' to mix with it. Perhaps I'm looking for something that doesn't exist.

Sorry to do in reply, how do i place a new thread/post?

The term Waterproof is often misleading, cement grouts are not effected by water so wont disintigrate, epoxy grouts are waterproof but i dont think you need to go this far, the tanking will stop any water that penetrates the grout from ingressing into the wall and wont effect the grout, a good cement based grout from mapei or bal would be my choice and as Dan says check that they are suitable for continous immersion. Though obviously there are many alternatives from other manufacturers.

Hope that helps a bit.

The only waterproof grout is epoxy grout. I would go for a good flexible grout such as Mapei or BAL and then seal it after installation to help reduce water ingress. Take the Unibond back to the shop

Kev

I agree with the guys above. Epoxy is the only waterproof grout and it is nasty to work with.

I use Ardex grouts and it says on the bag that they are suitable for swimming pools, so it's good enough for me and my customers .

I'm pretty sure Granfix sell there maxi grout range as waterproof. Got some in the van but its too cold and dark to check tonight, will let you know tomorrow.
Lee

Cementious grouts are NOT waterproof. Period. A grout being waterproof would indicate that water does not penetrate through it. Cementious grouts are generally water resistant, which means they don't deteriorate under the influence of water. That does not mean they're waterproof, and marketing cementious grout as waterproof should be illegal, and probably is. The only truly waterproof grouts around are epoxy grouts.

Most modern cementious grouts will do fine on a wetroom floor. Buy from the large, well known brands, such as Ardex, Mapei, or Bal, and you'll do just fine.