Just had my kitchen floor tiled with 18" "star galaxy" granite floor tiles. The builder used 4mm spacers (which look a bit wide - is this normal for granite?) and "anthracite" coloured grout. The problem is, the grout has gone light grey and looks wrong. What could cause this & what (short of raking-out & re-grouting) can I do?

Spacing of tiles varies it all depends on the quality of the tiles as far as size goes. Personally I like to keep granite at 1.5-2mm spacing for a classy look but 4mm would be considered acceptable.

The discolouring of the black grout is caused by using too much water whilst washing down the grout. Darker coloured grouts need to be washed off with a barely damp almost dry sponge to avoid bleaching or oxide stripping.

A quick fix would simply use a permanent felt tip marker in black run carefully down the grout lines.

Just remember like colouring in as a kid stay inside the lines LOL

Professional Grout colourant is the way to go

Kev

The grout spacing can be a function of the substrate you are tiling onto. if you have a timber floor, I personally would lay with a larger grout line than if it was on concrete to allow for movement.

As it was, I feel the builder should have discussed your requirements and views with you before commencing.

The grouting going light grey-ish could be effloresecence.......what make of grout is it..?

has anyone continued this thread as I've got similar problem with black granfix. It looks for me as effloresecense but how to tackle it now? Can I regrout on top of it as there is still some room for a millimetre of grout?

Cant you try recolouring with Tradetiler Universeal Grout Colour It works great.

As above, dont try just grouting over the top, if it needs re grouting then the grout will need to be cut out first.

Surprisingly the grout is still soft(ish). So I dug in with stanley knife and grouted a part of the floor to see results after it's dry. The owners say they like the grey colour anyway as it shows the tiles better :/

Originally Posted by vosnack

Surprisingly the grout is still soft(ish). So I dug in with stanley knife and grouted a part of the floor to see results after it's dry. The owners say they like the grey colour anyway as it shows the tiles better :/

how long has the grout been in

The grout shouldnt be soft?

Originally Posted by Rich

The grout shouldnt be soft?

I agree. the floor has either been grouted in near freezing conditions, or it is out of date (or contaminated) which can prevent it setting properly

Ive used Mapei Fuga Fresca grout colourant, dead easy to use and the same colours as their grout range. Ive used on grout that isnt Mapei.

The grout been in for a night before I came back to it and raked it. I thought about possibility of it being out of date but it only passed my mind and I ignored the thought.

One night in cold conditions i doubt it had set