Spalling Concrete Repair Singapore

HDB describes spalling concrete as common in older buildings, especially in damp areas such as kitchens and toilets. It is largely caused by carbonation, which makes the steel bars in the ceiling slab corrode, so the concrete cover cracks and bulges. Look for:

• hairline cracks in the ceiling paint, often in straight lines;
• brown or orange rust stains along those cracks;
• a patch of ceiling that bulges or sounds hollow when tapped;
• flakes of paint or concrete on the floor below;
• exposed, rusted steel bars where a piece has already fallen.

A brown ring with soft, bubbling paint is more likely a leak from above. You can have both at once. Our guide to spalling concrete in HDB flats explains the difference.

We follow the repair steps HDB publishes for spalling concrete:

1. Remove the loose and spalled concrete until sound concrete is reached.
2. Scrape and clean the exposed steel bars, and wire-brush off the rust.
3. Apply 2 coats of anti-rust paint to the steel bars.
4. Apply a bonding agent so the new mortar adheres properly.
5. Patch the hacked area with polymer-modified cement mortar.
6. Paint over the patch to match the rest of the ceiling.

The most common failed repair is plaster or filler skimmed straight over rusty steel. The rust keeps growing and the patch falls off again. Treating the steel is what makes the repair last.

Typical 2026 market prices. The final price depends on the size and number of patches, how deep the rust goes, and the ceiling height.

If the ceiling also has mould, we treat it in the same visit and finish with anti-mould paint; see mould removal. For other ceiling damage, see ceiling repair.

• The owner. HDB states that as the home owner, you are responsible for preventing spalling concrete in your flat through regular maintenance, and for any repair work required.
• Large patches. HDB advises engaging a contractor promptly if the patch is large, before more concrete falls and causes injury.
• New flats. All new HDB flats have a 1-year Defects Liability Period from key collection. Within that period, submit a rectification request to HDB instead of paying for a repair.
• Older flats. If the spalling is due to wear and tear, ask HDB about its Goodwill Repair Assistance scheme before you pay for a private repair, since HDB may arrange and co-pay part of the work.

While waiting for a repair, HDB suggests removing loose concrete carefully with gloves, eyewear and a helmet, so it does not fall on anyone. Only remove pieces that are already loose.

HDB lists three ways to prevent spalling concrete:

• Paint ceilings regularly. Paint protects the ceiling and helps prevent carbonation. See our HDB painting service.
• Seal cracks and holes. Seal ceiling cracks and any unused holes, such as those left after a ceiling fixture is removed. Our hole repair service handles these.
• Ventilate damp rooms. Open windows, vents or doors in the kitchen, toilet and bathroom when they are not in use.

1. A photo of the whole ceiling, so we can see where the patch is.
2. Close-ups of the cracks, rust stains or exposed steel.
3. A rough size of each patch, for example using a ruler or your hand for scale.
4. Which room it is in, and whether concrete has already fallen.
5. Your flat type and roughly how old the block is.

We take spalling concrete repair jobs islandwide. Our workshop is at Mandai Estate, so Woodlands, Yishun, Sembawang and Admiralty are the quickest for us to reach, and we regularly cover Punggol, Sengkang, Ang Mo Kio, Tampines, Bedok, Jurong and the rest of Singapore.