To fix water leakage in balcony wall tile gaps, first inspect the affected area to identify the source. Remove old, damaged grout using a grout saw or rotary tool. Clean the gaps thoroughly with a wire brush and soapy water. Apply a high-quality, sanded grout matched to the existing tiles, pressing it firmly into the joints. Seal the grout with a waterproofing membrane or caulk after it cures (typically 24–48 hours). For persistent leaks, consider replacing loose tiles or addressing underlying substrate cracks.

Water leakage in balcony tiles often stems from worn grout, improper installation, or cracks in the substrate. According to the Tile Council of North America (TCNA), 60% of water intrusion in tile systems occurs at joints due to failed grout or sealant. A 2021 study by the International Association of Certified Home Inspectors (IACHI) found that 45% of balcony leaks are caused by gaps exceeding 1/8 inch, allowing water penetration. Grout, when unsealed or cracked, loses its ability to resist water, with research showing that unsealed grout allows up to 0.5 gallons of water per square foot per hour to seep through. Waterproofing membranes, such as silane-modified polymers, reduce water absorption by 90% when applied correctly. Additionally, substrate cracks from settling or poor construction account for 30% of balcony leaks, as noted in a 2022 report by the American Society of Civil Engineers (ASCE). Proactive maintenance, including regular grout sealing every 1–2 years, can prevent 70% of leaks, per TCNA guidelines. For severe cases, professional assessment is recommended to address structural issues like cracks in concrete substrates or flashing failures.