Splotchy grey grout. Again - Tile Advice

[andy8758]

It happened before. Using BAL gunmetal (silver grey) grout for a kitchen splashback of metro tiles. It went "splotchy" (dark patches in grout). I got through all the "overhydrated" arguments (mix too wet or too much sponging water after filling), which I am pretty convinced did not apply, I mix all grouts the same way and to the same consistency.

Happened again last week, This time with Mapei Ultracolour mid grey.

This time, the bathroom had two types of tile. Ceramic glazed in shower (where the splotchiness occurred), and porcelain on other wall and floor sections. Guess what - I used the same grout in both (one mix for both sections), but the porcelain tiles were fine - the grout colour was perfectly even.

I cornered a BAL rep soon after first incident. He suggested they had found some ceramic tiles dried the grout inconsistently causing an effect similar to overhydration. I believe this is the cause of last weeks poor grout finish.

Anyone else encountered this problem?

 

[Flintstone]

That's a joke on there part. Basically they are saying it's not suitable for ceramic tiles?
I have recently done a job with metro tiles on the wall and slate on the floor and the same grout, tilemaster mid grey has dried darker on the walls than the floor. Consistent tho and not patchy

 

[Spare Tool]

Found Webber greys to dry patchy, happened so often I've given up on it, been using TM and Ultra grouts recently depending which shop I'm in and as yet no problems

 

[Blunt Tool]

Tiler mate up here had similar with Mapei 112 mid grey in ceramic tiled bathroom. CTD gave him numbers for Mapei support. Spoke to him a few days later and was telling me they told him to finely sand the blotchy areas with fine grade sponge sand block as was only on surface, they said they've had similar enquiries. Mate said right enough it worked.

 

[Lucas D]

It must be moisture, I had that when it was heavy raining outside. It never happened on sunny days to me. I had to use Fuga Fresca to achieve regular colour. What a nightmare.

 

[Spare Tool]

It must be moisture, I had that when it was heavy raining outside. It never happened on sunny days to me. I had to use Fuga Fresca to achieve regular colour. What a nightmare.

Eh?? You were grouting in the rain?

 

[Lucas D]

No.... I should say humidity

 

[On one]

Just a suggestion.......was the tile adhesive dry enough before you started tiling, and I mean by the 'the book'.
We all do it, I have done it, where you start grouting as soon as it it is reasonably possible, but not long enough by 'the book' and the remaining moisture in the adhesive is giving a patchy colour?

 

[Italy]

Tiler mate up here had similar with Mapei 112 mid grey in ceramic tiled bathroom. CTD gave him numbers for Mapei support. Spoke to him a few days later and was telling me they told him to finely sand the blotchy areas with fine grade sponge sand block as was only on surface, they said they've had similar enquiries. Mate said right enough it worked.

Yes, I confirm, I often use sandpaper, with these problems. (True @Andystiletiling ?) .
One of the problems, with some ceramic tiles,
Have some tile edges
With enamel and some edges no.

 

[Spare Tool]

Yes, I confirm, I often use sandpaper, with these problems. (True @Andystiletiling ?) .
One of the problems, with some ceramic tiles,
Have some tile edges
With enamel and some edges no.

Sandpaper is definitely the answer

 

[Unused Account 1]

I had same with mapei cement grey mate

 

[Spare Tool]

I had same with mapei cement grey mate

Did you try sandin it?

 

[J Sid]

you can get help for this sand paper fetish you have Andy

 

[Spare Tool]

you can get help for this sand paper fetish you have Andy

Mmmmm...