I bought a renovated home, the ceramic tile on the bathroom floor is coming loose in certain places. The grout is breaking up and causing an unpleasant grittiness against my bare feet. I laid a rug down to escentially cover the floor so my feet will stay clean and not track the loosening grout through the rest of the house. Is there an easy way to fix this, or would it require removing the entire flooring and relaying the tile to do a good job. I suspect the tile was laid directly on the subfloor and some nails where used versus screws. The nails are now working themselves out which is causing the tiles to move and break up the grout. The entire floor isn't doing this, so I am unsure if it is isolated to a few spots, or if the entire flooring will eventually have a problem. I know the tile itself comes in a larger square pattern with 1inch and 3 inch tiles being held together with what appears to be string. The seller was kind enough to leave me the leftover tiles so if it is possible to repair in patches by finding the nails, replacing w/ screws and relaying the loosened tiles, I have replacements.... Wondering know if he knew I would need them... hmmm Any thoughts on the best way to tackle would be greatly appreciated. :)

I have a 16 year old ceramic tile shower where in a few places some of the grout is coming out from between the tiles, and in other places its just warn off over time to the point that the grout only comes about half way up the side of the tile. So I've decided to regrout. All the tiles are solid. I know I need to get any loose grout out of there, but allot of the grout is still solid and I'd like to reduce my chances of damaging any tile by leaving anything that's still solid. The floor tiles are spaced 1/8th inch, the wall tiles are 1/16th inch. My questions are - how much of the old grout do I need to remove for the new grout to adhere properly? Will new grout adhere to the old grout? What's the minimum depth I can get away with?