S
stuart tactile
have just laid a slate floor. everything ok until grout set. was meant to be charcole but about 10% charcole 10% light grey 80% white! looks really bad. i was told its probably effervecence residue and an acidic cleaner would bring it off, but have tried and, if anything just looks whiter! can anyone help? i've dug out about 3mm to see if its dark under the surface but it doesnt appear to be. please help!