Black Grout Is Now Grey

[TonOfSand]

Howdy

I've recently applied black grout between my tiles, left them for a while and rubbed clean with a sponge but it quickly turned light grey except for a few areas where it wasn't easy to rub down with sponge ('cos of painted walls). While it looks okay, can anyone provide an explanation or a remedy? Ta.

 

[Richard C]

Who’s/what grout was it? Some are blacker than others but what usually happens is powdery residue gets into the rough surface of conventional grout & lightens the colour, probably what's happened in your case. Epoxy grout (expensive & trickier to work with) will avoid this to a large extent but now you’ve got what you have, try sealing which should bring the colour back.

 

[tictic]

Sounds like effloresarance.....

Will need a good cleaner...google...

Aquamix,lithofin,ltp,fila,universal...there are others,just look for there stain removers/acid ones...ect..then a grout sealer/colourant reviver ect..