Answer:
(1) The recess must be made around all drainage pipes, through-holes, and corners, and the reinforcement must be done with water-based resin mortar or non-shrinkage waterproof cement.
(2) It is best to use waterproof materials that are hand-applied rubber products with a coating (this prevents the accumulation of water on the top layer from causing hydrolysis of the PU), with a coating thickness of two layers or more.
(3) If waterproof felt-type sheet-shaped waterproofing materials are used, careful construction is required at the corner and connection points; even the slightest error must be avoided.