Roof leaks are a nightmare for landed homes and top-floor HDB units. One heavy thunderstorm can cause ceiling collapse, electrical damage, and mould. Here’s what to check.
For HDB Residents
- Roof is HDB’s responsibility. Report to Town Council immediately.
- But if leak is from your own AC ledge or planter box, you pay.
For Landed & Condo Penthouses – Common Causes
1. Cracked or Missing Roof Tiles (Terracotta/Concrete)
- Sign: Daylight visible from attic. Water stain below.
- Fix: Replace individual tiles. Use colour-matched mortar.
2. Flashing Deterioration
- What: Metal strips around chimneys, vents, skylights.
- Problem: Rust or lifted seams.
- Fix: Re-seal with polyurethane sealant or replace flashing.
3. Ponding Water (Flat Roofs)
- Cause: Poor drainage or sagging roof deck.
- Fix: Add roof drains or apply tapered insulation to direct water.
4. Blistering or Bubbles in Torch-On Membrane
- Cause: Trapped moisture vapor from old roof.
- Fix: Cut out blister, re-melt membrane.
5. Pipe Penetration Leaks
- Cause: Failed rubber boot around AC or exhaust pipes.
- Fix: Apply liquid rubber sealant or replace boot.
6. Parapet Wall Cracks
- Cause: Movement between wall & roof slab.
- Fix: Install metal coping cap or apply elastomeric coating.
Emergency Temporary Fix (Before Professional Repair)
- Use heavy-duty tarpaulin weighted with sandbags.
- Do NOT apply silicone caulk while raining – it won’t bond.
Professional Repair Costs in Singapore
| Repair type | Cost range |
|---|---|
| Tile replacement (per tile) | 30–80 |
| Flashing repair | 200–600 |
| Liquid membrane coating (per sqm) | 40–80 |
| Full torch-on overlay (per sqm) | 70–120 |
| Leak detection (thermal imaging) | 250–450 |
Prevention Tips
- Inspect roof twice a year (before monsoon seasons: Nov–Jan & Jun–Aug)
- Keep gutters and downspouts clear
- Apply reflective roof coating every 5 years (also lowers indoor temp)
Conclusion
Don’t ignore a small stain on your ceiling. It means water has already penetrated. Call a BCA-licensed roofing specialist for a moisture scan.
