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Spalling Concrete in Singapore: What It Is and How to Fix It
- Earnest Lim
- Jul 5, 2021
- 3 min read
Updated: Jun 14
TL;DR:
Spalling concrete is when concrete chips, flakes, or breaks off due to corrosion or carbonation
Common in older condominiums, landed homes, and commercial high-rise buildings
Causes include moisture, poor ventilation, and steel corrosion
Regular painting and sealing cracks can help prevent it
Immediate repair is crucial to avoid safety risks and costly structural damage
Introduction: Why Spalling Concrete Is a Serious Concern in Singapore
You’ve seen it before—patchy ceilings with flaking paint or chunks of concrete falling off balconies or corridors. In Singapore, especially in ageing condominiums and older properties, spalling concrete is a common problem. But it’s not just an eyesore. Left unattended, it can pose real safety risks to residents and compromise the structural integrity of your building.
This guide will help you understand what spalling concrete is, how to spot it early, and what you can do to prevent or repair it.
Table of Contents
What Is Spalling Concrete?
Spalling concrete, also called scaling, happens when parts of the concrete surface chip, crack, or break away. It often exposes the coarse aggregate beneath and, in more severe cases, the reinforcing steel (rebars) inside. These patches can grow up to 15 cm or more in diameter and may extend several centimetres deep.
You’ll most commonly find spalling on:
Ceilings (especially in toilets or kitchens)
Balcony undersides
Corridor slabs in residential or commercial blocks
Carpark structures and beams
Once spalling is visible, it should be professionally assessed and repaired quickly to avoid injuries or structural failures.
What Causes Spalling Concrete?
The main culprit behind concrete spalling is carbonation—a natural deterioration process where carbon dioxide in the air reacts with calcium in the concrete, lowering its pH and making it less protective for embedded steel.
As steel corrodes, it expands, causing the surrounding concrete to crack and bulge. Other contributing factors include:
Common Causes:
Moisture infiltration into cracks and surface voids
Corrosion of embedded reinforcing steel
Poor-quality or insufficient concrete cover
Alkali-Silica Reaction (ASR)
Fire exposure (extreme heat causes internal steam pressure)
Improper construction joints
Lack of ventilation in humid spaces
How to Identify Spalling Early
Early detection is key. Look out for:
Bubbling or flaking ceiling paint
Pitting or patchy concrete surfaces
Exposed aggregate or rusty steel bars
Hollow sounds when tapping on concrete surfaces
For concealed or large-scale damage, engage a professional to perform a non-destructive test or structural inspection.
How to Prevent Spalling Concrete
While carbonation is inevitable over time, you can slow its progress and reduce risk:
1. Paint Ceilings Frequently Use anti-carbonation paint and repaint ceilings every 3–5 years. This helps block moisture entry and slows carbonation.
2. Seal Cracks and Holes Promptly Use hydraulic cement to fill any cracks or unused drill holes. This prevents water from entering and starting corrosion from within.
3. Improve Ventilation Bathrooms and kitchens should be well-ventilated. Keep windows and exhaust fans open when not in use to reduce humidity.
How Spalling Concrete Is Repaired
A professional repair typically involves:
Removing all loose and damaged concrete
Cleaning and treating exposed steel reinforcement
Applying bonding agents and repair mortar
Finishing with anti-carbonation paint
Depending on the severity, scaffolding or rope access may be required for safe and thorough repairs.
Why Immediate Action Matters
In Singapore, there have been multiple cases where falling concrete from ceilings or façade elements caused injury. Spalling is not just cosmetic—if left unrepaired, it can lead to:
Water leakage and seepage
Rusted reinforcements compromising load capacity
Higher repair costs over time
Violation of BCA safety and maintenance guidelines
Call Hydro-seal for Concrete Repairs in Singapore
Hydro-seal Engineering has been trusted by homeowners, MCSTs, and property managers since 1995. Whether you're dealing with minor spalls or large concrete delamination, our experienced team is here to help.
📞 Call 6289 6811 or 📧 email us at enquiry@hydroseal.com.sg to schedule a free inspection.
FAQs About Spalling Concrete in Singapore
Q: What is the most common cause of concrete spalling in Singapore? A: Carbonation, especially in humid environments like kitchens or toilets.
Q: Can I fix concrete spalling myself?A: Small hairline cracks may be filled, but deep spalls and rusted rebars need professional repair.
Q: Is spalling covered under HDB maintenance?A: For HDB flats, repairs inside the unit (like ceilings) are typically the owner's responsibility.
Q: How long does a spalling repair last?A: With proper application and repainting cycles, repairs can last over a decade.
Don't Wait Until It Falls—Fix Spalling Concrete Today
If you notice any cracks, flaking, or rust stains in your ceiling or wall, don’t delay. Schedule a professional inspection before the problem spreads.
📞 Call Hydro-seal at 6289 6811 for a no-obligation consultation today.
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