If there are no visible leaks in your bathroom but your neighbor below is experiencing water leakage, there could be several potential causes to consider:
Plumbing System: There might be an issue with the plumbing system in the walls or floor, such as leaking pipes or fittings. These hidden leaks could be causing water to seep into your neighbor's bathroom without being immediately visible in your own.
Faulty Sealant or Grout: The sealant or grout around your shower, bathtub, or other fixtures may be deteriorating or improperly installed, allowing water to penetrate and seep through to the floor below. This can occur even if there are no visible signs of water leakage within your bathroom.
Drainage Problems: Poor drainage within your bathroom can lead to water pooling or overflowing, which may find its way into your neighbor's unit. This could be caused by clogged or improperly installed drains, inadequate slope in the floor, or other drainage issues.
Structural Defects: It's possible that there are structural defects in the building, such as compromised waterproofing membranes, faulty construction, or cracks in the walls or floors. These defects can allow water to travel through the building materials and affect neighboring units.
Condensation or Moisture Migration: Excessive condensation or moisture buildup within your bathroom can accumulate and eventually find its way into adjacent units. This can be caused by insufficient ventilation, high humidity levels, or inadequate insulation.
In any case, it's crucial to investigate the issue promptly to prevent further damage and address the source of the water leakage. Consider contacting a licensed plumber or a professional contractor experienced in diagnosing and resolving water leakage problems to conduct a thorough inspection and identify the underlying cause.