I have a problem with a limestone floor which shows discolouring after grouting. It was sealed twice with LTP Mattstone before I grouted it but I.m worried I've caused some irreversible damage. I've seen other pictures of framing caused by grout but this is different. It is mainly lengthways down the two sides. I've tried some intensive cleaners (alkaline based) and they did very little. As a last resort I tried bleach on one and this worked quite well. Unfortunately it's still not good enough and you can still see the shading, especially in the sunlight. I'm looking for advice from people who have positive things to say other than fitter error (my ego took a bashing on this one). I'm really hoping someone has experience in rectifying this problem as removing and replacing is simply not an option. Cheers
