Hi I’d be very grateful for advice. I had a bathroom fitted a couple of months ago and have just noticed that many of the metro tiles have spidery cracks in them. There is no pattern to them - some cracks run up through a couple of tiles but they’re not all adjacent. I’m sure they weren’t there when they were put up. My tiler can’t explain it. It is just on one wall. We have a new cast iron bath in that room which went in after the tiles were laid as did a new velux window. But there are no new visible cracks in any other walls elsewhere in the house. I assume we’ll have to have it all retiled but I’d like to understand why it happened so it doesn’t happen again.