Natural stone tiles - sealing and grouting

[decimal_dust]

I am new to tiling and have just put up some natural stone tiles as a splashback around my bathroom sink and bath.

I have some specialist sealer, but I am not sure whether I should apply this after grouting or before grouting?

The tile shop sold me some grout filler knowing this was the case, but on later reading the instructions it states that the grout is water-resistant but not waterproof. I have search for waterproof grout, but the only ones I can find are suitable only for ceramic tiles etc and state they must not be used with natural stone. Is there a waterproof grout that someone could recommend for use with natural stone?

Thanks in advance.

 

[michaela]

Sorry if this information comes a bit late, you could use Mapei untracolor plus grout which is water repellant, it has a bio block which helps to prevent mould forming and is used in swimming pools, bathrooms etc. It is usually available from specialist tile shops. As for sealing the tiles after fixing they should be thoroughly cleaned and then left to dry completely, then sealed. (It is coverage not quantity that counts). Allow the sealer to sink in to the tiles for at least 3- 4 hours (but no longer that 6) then wipe up any surplus sealant. After the sealant has dried then grout the tiles.
After you have finished all of this and the tiles are cleaned of grout dust you could apply a specialist wax polish as added protection. (Lthofin products are excellent, again only available from specialist shops, but they do have a website if you want to have a look). Hope all this helps, although you have probably managed already.