Concrete spalling is the most misunderstood defect in Singapore property maintenance. The visible chunk that fell off the ceiling is the symptom. The real defect is the corroding rebar behind it — and the moisture that woke the rebar up. Treat one without the other and the spall comes back in 12–18 months.

What we repair.

Spalling concrete — ceilings, soffits, columns, beams, balcony undersides.
Structural cracks — diagonal, hairline and dynamic. Diagnosis before fix.
Hollow render — failed plaster on façades and internal walls.
Rebar corrosion — exposed steel, cracked cover concrete, rust staining.
Carbonation-induced damage — older RC buildings with low pH cover concrete.
Honeycomb voids — original-build defects exposed during demolition.

Don't paint over it. A spalling ceiling is a structural issue, not a cosmetic one. Painting hides the warning while corrosion accelerates. The next chunk to fall will be bigger.

Concrete spalling repair — exposed rebar treated with corrosion inhibitor before patch.

Why concrete spalls.

Reinforced concrete works because the alkaline cement passivates the steel inside. When water and CO₂ penetrate the cover concrete, two things happen:

Carbonation drops the pH around the rebar. The passive layer breaks down.
Corrosion starts. Rust expands up to 7× the original steel volume, pushing the cover concrete off in chunks.

Once that cycle starts, every monsoon accelerates it. The fix is structural, not cosmetic: stop the moisture, treat the steel, restore the cover, protect the surface.

Standard repair scope.

Diagnostic survey. Map every spalled area. Sound-test surrounding concrete for hidden voids.
Hack to sound concrete. Remove all loose, carbonated and contaminated cover concrete around the defect.
Expose & clean rebar. Wire-brush or grit-blast all corroded steel back to bright metal.
Rebar treatment. Two-coat zinc-rich anti-corrosion primer applied to the cleaned rebar.
Bonding slurry. Polymer-modified bonding coat on the exposed substrate.
Patch repair. Polymer-modified, shrinkage-compensated repair mortar applied in layers to the original profile.
Cure. Damp curing for 48–72 hours.
Protective coating. Anti-carbonation or elastomeric coating to slow re-ingress.
Source rectification. If the spall was caused by an upstream leak, the leak is fixed before final paint — see waterproofing.
Photo report & warranty.

"Patching the concrete without treating the rebar is like changing the bandage and ignoring the wound."

Building repair FAQs.

Is spalling concrete dangerous?+

Yes. A chunk of falling concrete from a ceiling, balcony or beam can injure occupants. Active spalling should be cordoned off and treated within weeks, not months.

What's the difference between spalling and hollow render?+

Spalling is structural concrete and steel; hollow render is just the plaster topping that has lost bond. Spalling is more serious. Both need treatment but the scope is different.

Will the repair match my existing ceiling?+

Yes. Final skim and paint are matched closely to the surrounding finish.

Related pages: Ceiling leak diagnosis · External wall waterproofing · Painting

Concrete spalling, cracks & render repair.

What we repair.

Why concrete spalls.

Standard repair scope.

Building repair FAQs.

Stop the next chunk falling.