Leak & waterproofing encyclopaedia
Guides in this topic, paired with courses and open dates so you can move from reading to hands-on learning.
Rooftop PU waterproofing: primer, body coats, topcoat—and DIY limits
PU roof waterproofing is not one brush coat. Primer, 2–3 body coats and a UV topcoat, plus detailing at parapets and drains, make a complete system. Know what you can DIY.
Recurring wall efflorescence? Stop the water before skim-coating
If white powder and peeling paint keep returning, the water path is still open. Causes, how to find the source, the correct order of works, and when to call a pro.
Leak tracing basics: how to find the water source
Wall damp or a dripping ceiling is not always from directly above. Trace leaks in order: log timing, eliminate zones, then repair—use simple checks before opening walls.
Common DIY Mistakes That Make Seepage Worse
Seven homeowner DIY habits that worsen leaks—wrong sealants, sealing vapour paths, repairing before finding the source—and safer alternatives.
Emergency Stop-Leak vs Permanent Repair: When Temporary Is Enough
Safe temporary steps when a ceiling drips or a window leaks, why surface sprays often fail, and when permanent diagnosis and repair are required.
Seepage and Nuisance: General Information
Prolonged seepage may raise hygiene/nuisance issues—general information only, not legal advice.
AC Ledge Seepage: Ponding, Drainage and Joints
Ponding or failed joints on AC ledges often leak indoors after storms—check drainage before DIY or exterior works.
Upper-Floor Seepage Responsibility: Communication and Evidence
Cross-unit seepage needs early communication and evidence; departmental and civil tracks differ—general info only.
Joint Office Investigation Stages: Key Points for Owners
Overview of Stages I–III, advisory repair notices and inspection-fee recovery (general information).
Finding a Leak Source: Observation, Logging and Tool Limits
Source-finding starts with structured observation; IR tools help but never prove a source alone.
External Wall Seepage Into Interiors
Cracks and hollow rendering can drive rain into walls—usually a professional job; owners should keep evidence.
Window and Windowsill Seepage After Wind and Rain
Windowsill leaks are common—check sealant and drainage before DIY resealing or external frame repair.
Bathroom Leaks: Shower Trays, Floors and Common Blind Spots
Bathroom leaks often involve trays, drainage and joints—separate in-flat issues from effects downstairs.
Ceiling Water Seepage: Causes and What To Do Next
Ceiling stains often track upper floors, pipes or window paths—log first, then observe, complain or repair.
Water Seepage Between Flats: Finding the Cause and Joint Office Guidance
From 16 July 2026 the Joint Office uses new seepage procedures: advisory repair notices, a 28-day window, and inspection-cost recovery of at least HK$17,000.
Owner Water Seepage Self-Check: 6 Safe Diagnostic Steps
A six-step homeowner guide to observe ceilings, walls, windows and drains, log stains safely, and judge when to call professionals—without blind repairs.
Common Household Seepage Types: Ceiling, Wall, Floor, Window and Roof
Hong Kong household seepage usually falls into pipe leaks, upper-floor water use, failed floor waterproofing, or rain through roof/wall/windows—symptoms point to responsibility and repair direction.