Run off the corner edges of cement that are connected to the edge of the bathtub to prevent leakage in case of more cement sealing action tho prevent uncle to trapped underneath the bathtub more affect the primary structure.
Use the mortar off the edges connected to the water bath to prevent leakage of grout cracked prevent water flowing into custody under the bath water, affecting the main structure.
Use close to the curb connected to edge bathtub "operation to prevent leakage of cement grout shall เทาะป้องกัน" leading to lock under the bathtub "operation on main structure