What are the causes of water under a tile floor.
Water leaking through tile grout.
The best way to tell if.
Maybe a plumbing leak or maybe the drain is restricted in the shower and water is not allowed to fully drain away.
Leaking drainpipes in a shower or a bathroom plug will let water underneath tile.
It appears you have some sort of leak.
There should be proper flashing the membrane should be sloped to a drain that has weep holes to allow the water through.
Cracks can develop in the grout between the tiles allowing moisture to seep through.
Can shower water leak through grout.
Check the ceramic tile walls surrounding your tub or shower.
If water is oozing up through the grout joints and it is becoming moldy then water is not able to drain away.
If the grout becomes damaged on the floor it will give water a chance to slip through the gaps and under.
They may have waterproofed the underlying deck but they could have made mistakes.
If it is leaking then it isn t fully waterproof.
This tile needs periodic maintenance.
Leakages in the shower are most often the result of grout failure.