u/GasPrestigious7811

Anyone know why there is this mark?
▲ 3 r/Plumbing+1 crossposts

Anyone know why there is this mark?

Hi, I cleaned and sealed this porous marble tile like three times but there is a mark like this that is showing, anyone know why?

Could it be that I didn’t use bitumen under the flooring so moisture is rising!

u/GasPrestigious7811 — 19 hours ago