M
m3fitter
cracks opening on heating and closing on cooling means a serious problem caused by the floor trying to belly upwards due to thermal expansion. This wil be the result of one of, or a combination of, two things. first thermal expansion and second lack of facility for movement in the form of movement joints.
have you put any movement joints in your 90m2 of porcs??
The main cracked area only has a max diameter of 4.6m wall to wall, left 6-8mm expansion to plaster, on commercial or swimming pool surrounds would allow schluter / genesis expansion joints every 5m linear, but domestic, multi room, largest area is 30m2 in a room.. cracking is not in an isolated grout line.. but over a 30m2 area, fine cracks, definitely expansion in all directions ?