Help! Grout staining porcelain tiles problem

[Gumposam]

Hi everyone,

I've just completed laying a bathroom floor with 100x100mm black and white unglazed porcelain tiles ( PEI rated 5) . I've also knocked up a test piece on which to test the grout, as I'm a bit wary of the textured surface of these unglazed tiles. The intended grout colour is black. I have treated the tiles with Lithonfin stain stop, same way as I have treated my test piece.

As you can see, my grout test has come out terribly, with the white tiles looking grey and like they have a 5 o'clock shadow. What would the best course of action be here? Treat with something else? What would you recommend?

Many thanks in advance

 

[Tile Shop]

Had a couple of queries like this recently. One option, grout them as they are, and clean them with something like the LTP Grout stain remover and a black pad emulsifying pad, but the best solution is to put a sealer over them first before grouting. They're porcelain, so this is not essential, but will help..... you can apply a temporary coat of their MPG sealer. This will sit on the surface and be naturally removed during the cleaning off process. Another one is the BAL protective sealer.

But be careful with both, not to get it down the joints as if it attaches to the sides of the tiles, it can reduce the bond strength of the grout which can lead to it cracking further down the line.

 

[Gumposam]

Thanks Paul , I'm doing a test piece now and I'll let you know how I get on

 

[Rookery]

I'd use Lithofin Protective Impregnator rather than Satin Stop but no doubt Bob will be along soon to advise.

 

[Andy Allen]

Use a different colour grout !!
Black seems to stain everything..

 

[Gumposam]

Well i gave it a go with an impregnating sealer and it's improved the tile by about 75% , but it's still grimy looking. I've been using Weber Joint Pro in black. so it looks like the only sensible option here is to abandon the black grout altogether - what would you suggest? Does grey grout have any dye in it?

 

[Bill]

don't use black grout - trust me it is terrible and stains almost everything no matter what impregnator you use.

Use a dark grey grout for floors and within a few weeks of washing, the grout will be black anyhoo.

If you insist on a black grout, try anthracite from the mapei range. Seems about the best one to me for cleaning off.

Nice tiling btw.

 

[Gumposam]

Thanks Tom, I'm proud of it as it's my first attempt - hence the inexperience - I'm okay with using grey or white, whatever gives the best finish. My worry now is that a white grout would stain a black tile in the same way, maybe that's not a problem though?

 

[Bill]

most white grouts won't stain but I advise you to use grey.

 

[Chalker]

Same tiles with Webber ivory grout.