Bathroom moisture may come from supply pipes, drain joints, fixture seals, or the waterproof layer. Diagnose before removing tiles.
Common warning signs
Mould at wall bases, damp grout, ceiling marks below, or a meter that moves when taps are off.
Likely causes
Aged sealant, loose drain connections, damaged concealed pipes, or a failed membrane.
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
Repair the confirmed joint or pipe; renew the membrane only when testing proves it is needed.. 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.