Maintenance
Concrete Spalling Repair in Singapore: Ceiling “Cancer”
If your ceiling is flaking with rusty metal showing through, that’s concrete spalling — sometimes called “concrete cancer”. It’s common in older HDB flats and, left alone, it spreads. Here’s what causes it and how it’s fixed.
Key takeaways
- Spalling = concrete flaking as the steel rebar inside rusts and expands.
- Common in older flats, often in bathrooms, kitchens and service areas.
- Moisture reaching the rebar is the root cause.
- Proper repair treats the rebar and addresses the moisture source.
What causes spalling
Concrete protects the steel reinforcement (rebar) inside it. When moisture — from humidity, leaks or failed waterproofing — reaches the rebar, it rusts and expands, pushing off the concrete cover. That’s the flaking and exposed rusty metal you see, most often on ceilings in older flats.
Why not ignore it
Spalling spreads — the more rebar that rusts, the more concrete detaches, and falling concrete is a hazard. It also signals ongoing moisture that may be damaging more than you can see.
How it’s repaired
Proper repair means removing the loose concrete, treating the exposed rebar (removing rust and applying an anti-rust treatment), then reinstating with a suitable repair mortar and finish. Crucially, the moisture source — often a leak or waterproofing failure — must be addressed, or it returns.
Frequently asked questions
What is concrete spalling? Concrete flaking off as the steel rebar inside rusts and expands — common in older flats.
Is spalling dangerous? It spreads and falling concrete is a hazard, so it’s best repaired promptly.
What causes it? Moisture reaching the rebar — from humidity, leaks or failed waterproofing.
Will it come back after repair? Not if the moisture source is fixed as well as the concrete.
Got flaking concrete?
We repair spalling — treating the rebar and the moisture cause. See our handyman service or our waterproofing service. Get a free assessment.
