Balcony waterproofing depends on falls, drainage, and threshold details—not coating alone.
Common warning signs
Long ponding, cracked grout, damp thresholds, or stains below.
Likely causes
Poor falls, a blocked drain, or failed threshold and membrane details.
Safe inspection steps
- Turn off the nearby power or water supply and protect people and furniture.
- Record when the mark appears, the weather, and recent water use; the visible stain may not be the source.
- Check joints, drains, supply pipes, and adjacent rooms. Use moisture or pressure testing when needed.
Recommended repair
Restore drainage and seals, renew waterproofing where needed, then flood-test.. Confirm the work area, materials, timing, and price before work. Test with water after completion and monitor nearby surfaces.
When to call immediately
Stop DIY work when water keeps dripping, finishes swell, mould spreads, or moisture is close to sockets or electrical panels. Phnom Penh humidity and heavy rain can make hidden damage grow quickly.