I'm hoping @PigletJohn might be around to answer this one!
We had large stone tiles laid on our kitchen floor four years ago as part of a refurb. Beneath them is underfloor heating. The grouting between some of the tiles has now cracked and in some places come out, leaving holes. We are also noticing that some tiles seem to give a tiny bit underfoot when we walk on them.
Obviously we need to get the floor re-grouted, but we're a bit surprised it's cracking and coming away after only four years. Should we be going back to the original builder and asking him to take a look at it? His work was guaranteed for ten years and he was brilliant to deal with, so I don't have any issue contacting him, I'm just wondering whether it's something we should expect to deal with ourselves as usual wear and tear.