Determining if a waterproof membrane is damaged isn't actually that complicated. We can start from several aspects to help you quickly pinpoint the problem. The core idea is: first, look at surface signs, then use tools to assist, and conduct professional testing if necessary.
Visual and Tactile Inspection (Quick Initial Screening)
Observe the Surface: Check tile grout, corners, and the outside of threshold stones for watermarks, efflorescence (white crystals), or mold.
Touch Test: Press your hand against the base of the wall or floor tiles for 3 seconds; feel for any unusual coldness or dampness.
Listen to the Sound: Gently tap the tiles; a hollow sound may indicate moisture in the mortar layer.
Professional Tool-Assisted Detection (Precise Location)
Infrared Thermal Imaging: Detects water accumulation under the waterproof layer; the temperature of the water accumulation area differs from the surrounding area.
Hygrometer: Measures the internal humidity of the wall; a moisture content >8% indicates a leak.
Fluorescent tracer: Inject a non-toxic tracer into the water on the floor. After 4-6 hours, shine a flashlight on the ceiling below. Water stains of the same color can accurately locate the leak point.
Simulation and Destructive Testing (Depth Confirmation)
Water Spray Test: Continuously spray the wall surface with a showerhead for 30 minutes, focusing on corners and pipe roots. Observe the floor below or adjacent walls for new damp marks within 2 hours.
Water Retention Test: Block the floor drain and fill with water to a depth of ≥25mm. Maintain this for at least 24 hours and observe for leaks below.
Destructive Testing: Drill holes at suspected damage points to take samples. Observe whether the waterproof layer is delaminated or powdery, and test the moisture content of the mortar layer.