i used the baskup board, the adhesive, then put the adhesive on each tile.
what type of tile good luck
i am more familiar with tiles falling off the wall. but yours are glued on so good they wont fall. The wall must be warping from water or steam and heat and the tiles wont bend with it so they crack.
Based on limited info I offer the following: Backer board doesn't compensate for a weak floor, which could be the culprit here. Foundation and/or framing is shifting (unstable) and causing the cracks.
The most likely culprit is the floor being too flexible. Many builders only build to support flooring such as hardwood flooring. The standard for that will let a 10 foot span flex up and down about 1/3 of an inch. That is too much for tile. Remember that bathtubs can be really heavy to support when filled with water and people. If you have access to the floor joist, you could measure their span and check the size against the American Wood Council's calculator. The higher the deflection limit the less they will bend. The deflection limit is how much they will bend. It could also be the house shifting. New Houses are problematic on this topic as the center supports sink, the foundation will move a bit, etc. In most soils this goes away after a time.
I would assume that you are talking about tiles on the floor ..that can be a number of things..#1 the floor has movement...should have 2 or more layers of structural plywood or similar product with joints overlapped...and be 1.25 thickness or more...#2 if you used adhesive (glue) is it for floor tiles and are they of the right size...most larger ties need a thinset type mortar...#3..are the tiles you used floor tiles...wall tiles should not be used on the floor...#4..if the adhesive does not support the entire tile any void could create a weak spot and direct pressure would crack the tile..#5.. the actual floor support may not be strong enough or the span too long thus you would get deflection (movement) if the floor moves or flexes your tiles will loosen or crack.
