Where must a waterproof membrane be placed in relation to the floor drain when it is above ground level?

The placement of a waterproof membrane in relation to a floor drain above ground level is critical to ensure proper drainage and protection against water intrusion. When the membrane is placed between the structural concrete floor and the topping slab, it acts as a barrier that prevents moisture from penetrating into the building's structure. This location allows any moisture that may accumulate to drain effectively, directing it toward the floor drain while keeping the underlying layers dry.

In this position, the membrane can effectively manage water from any source, whether it be from condensation, spills, or any leaks that might occur above it. Proper installation is essential, as it protects the integrity of the flooring system and prevents costly damage to the building's framework.

Other placement options would not achieve the same level of effectiveness in controlling moisture. For instance, placing the membrane on top of the drain would not fulfill its function, as it would only cover the drain rather than channeling water effectively. Likewise, positioning it underneath the topping slab may prevent excess moisture from escaping, leading to potential water buildup and damage. Finally, placing the membrane before the concrete pour might not ensure proper integration with the overall floor system, as the layers would not be aligned appropriately to work effectively together in terms of drainage.