Re-grouted floor, but it's not sticking

kelbal

Hiya. My downstairs floor has marble tiles throughout. The grout was looking dirty, and chipped in plenty of places, so with a combination of a grout scratching knife, and one of those small handheld electric grout removers, I dug out what I could, and spread fresh grout. It seems to have held ok in most of the area, but theres a good few spots where the tiles are so close together, the bit of fresh grout I can get in there is very minimal, just a tiny thin strip less than 1mm deep. When it dries and I mop the floor, this stuff just chips out. Not sure what to do now, as I have these patchy grout lines that are looking bad. Is there some sort of seal I can paint on over grout lines to reinforce them? Or any other alternatives?

Thanks

Madd002

You didn't take enough grout out. You should have done white vinegar and bread soda and an old toothbrush to get grout like new. I do this yearly.