Best grout for slate tiles on concrete floor

[Juliecwuk]

We used bagged Mapei adhesive to lay the tiles. Now looking for a decent grout for the tiles. Ideally i want a tubbed one to make it easier, Mapei seem to only do bagged grout, i worry about getting the right consistency for the grout when using a bagged grout....

we do have some Unibond flexible grout left from another room, but unfortunately its for wooden floors - unless that could work? i know people seem to hate Unibond though.

thanks

 

[Juliecwuk]

but if you guys recommend buying a bagged grout i will pop out to buy some as i want to do it right!

 

[Paul Finn]

Hi Julie.
I suppose it each to there own when it comes to personal preference on materials but I would much rather used a bagged powdered adhesive as opposed to a pre-mixed.

The only experience i've ever had with tubbed grout was a few years ago, and that's only because the customer had supplied materials. I found it to be to thick, hard to apply and difficult to wash off, just a nightmare basically, and with you grouting a slate floor with pores and cracks in the stone, you'd be better with a grout that will wash out a lot easier.

with the tiles been laid on a concrete floor, movement will be minimal so using a flexi grout certainly wont do it any harm although it isn't necessary. Whatever grout you decide to use just make sure its suitable for floors flexi or non flexi.

In my opinion, Mapei powdered grout it your best bet, its smooth and easy to apply and will wash off nicely. When trying to get the right consistencey just bear in mind that grout dosnt need much water compared to adhesive, so go easy with the water or add powder 1st then water 2nd if that helps, then wisk to a textured cream.

 

[Concrete guy]

How wide are the joints? If it's split random slate you could have some big gaps to fill. (I always used to use Ardex C2 for these - you could go up to 25mm with that stuff).

If it's machine cut they could be pretty regular - this will also define which grout you choose.