Spalling Concrete in Singapore: Causes, Rectification, and Prevention
Recently, there were two instances of concrete falling from the ceiling of HDB units.
FM Love 972 radio DJ Ho Ai Ling narrowly avoided injury on June 22 when a chunk of concrete fell from the toilet ceiling in her flat at Block 81 Commonwealth Close in Queenstown. Ms Ho moved into her 58-year-old flat 14 years ago.
Earlier, an elderly man was struck by falling spalling concrete from the ceiling of his toilet in his Yishun HDB flat on the morning of June 19, sustaining injuries to both his leg and head, requiring more than 10 stitches. The flat was completed 41 years ago.
Spalling concrete isn’t just an eyesore—it’s a safety concern!
Left unchecked, it can compromise the structural integrity of a property, putting occupants at risk. For home owners, addressing spalling promptly can also help maintain the value of your asset and avoid more expensive repairs in the future.
In this blog post, we’ll dive into the following key areas to equip you with all the knowledge you need on spalling concrete:
- What is Spalling Concrete
- What Causes Spalling Concrete
- How to Rectify Spalling Concrete
- Prevention and Maintenance Tips
- Who Bears the Responsibility for HDB Flats?
What is Spalling Concrete?
If you’ve ever noticed hairline cracks, flaking, or chunks of concrete breaking away from your ceiling, you’ve likely encountered spalling concrete. It’s a common issue in Singapore, especially given our tropical climate and the high humidity that comes with it.
Spalling concrete occurs when the surface of the concrete begins to break down, leading to cracks, flakes, or chunks falling off. It’s often a sign of underlying issues, such as corrosion of the steel reinforcement bars (rebars) within the concrete due to moisture Infiltration.
In Singapore’s climate, where buildings are constantly exposed to rain, humidity, and heat, spalling is a particularly common problem especially in older buildings or areas prone to moisture such as kitchens and bathrooms.
What Causes Spalling Concrete?
The main culprits of spalling concrete are:
Corrosion of Rebars
When moisture seeps into the concrete and reaches the rebars within, it reacts with the rebars, causing them to rust. As the rust expands, it creates pressure within the concrete, leading to cracks and eventually spalling.
Water Seepage
Singapore’s frequent rain and high humidity mean that water is always trying to find its way into structures. If the concrete isn’t properly sealed or if there are cracks, water can penetrate and weaken the material over time. This moisture is concrete's worst enemy.
Carbonisation
This natural deterioration process occurs when carbon dioxide in the air reacts with the concrete, making it more susceptible to damage.
Poor Workmanship or Materials
In some cases, spalling can be traced back to the quality of the concrete mix or the construction process. If the concrete wasn’t properly cured or if low-quality materials were used, it becomes more susceptible to damage.
Wear and Tear
Like anything else, concrete has a lifespan. Older buildings are more prone to spalling simply because the materials have been exposed to the elements for a longer period.
How to Rectify Spalling Concrete
If you’ve already noticed spalling, don’t panic—it’s fixable! Here’s how professionals typically address the issue:
Step 1: Assessment
The first step is to assess the extent of the damage. A structural engineer or contractor will inspect the affected area to determine the extent of the surface area that has been affected, some of which may be unobvious to homeowners. A simple sound test will provide insight to the invisible spalling ongoing within the concrete.
Step 2: Remove Loose Concrete
Any loose or damaged concrete is carefully hacked off to expose the rebars to ensures that repair work can be done on all the corroded steel.
Step 3: Treat Corrosion on Rebars
Treatment starts with sanding of the rebars with wire brush to remove the corrosion. The rebars are then treated with an anti-rust coating to prevent further corrosion.
Step 4: Surface Restoration
After the rebars are treated, concrete primer is applied to the exposed concrete before cement reinforced with cement strengthener is applied to fill in the gaps. Lastly, hard plaster is applied to restore the surface to a smooth finishing.
Step 5: Protective Coatings
Once the restoration is complete, the surface is painted over with sealer and quality paint coatings for added protection from moisture and to complete the fresh look of your surface.
Prevention and Maintenance Tips
As with most things in life, prevention is better than cure. The best way to deal with spalling concrete is to prevent it from happening in the first place! Here are some practical prevention tips to keep your concrete structures in top shape:
Regular Inspections
Keep an eye out for early signs of damage, like small cracks or signs of water damage. Minor damage are easier to treat when detected early and can save you from costly repairs down the line.
Seal Cracks Promptly
Don't let small cracks turn into big problems. Seal them as soon as you spot them to prevent further moisture from seeping into the concrete.
Proper Ventilation
Ensure good air circulation to reduce humidity levels and dry up the moisture quickly, especially in moisture-prone areas. Use a ceiling fan and keep those windows and doors open.
Regular maintenance can go a long way in preventing spalling concrete. These are some maintenance practices you can adopt:
Address Water Leaks
If you notice any leaks, fix them immediately to prevent water from seeping into the concrete.
Regular Application of Protective Coatings
Over time, protective coatings can wear off. Repaint your surfaces regularly every 3-5 years. For areas that are prone to moisture such as bathrooms and kitchens, it is recommended to paint every 3 years.
Who Bears the Responsibility for Spalling Concrete in HDB Flats?
This is one of the most common questions we get from homeowners affected by spalling concrete. Is it theirs, HDB or Town Council’s responsibility to repair spalling concrete?
HDB guidelines states that “homeowners are responsible for the prevention and repair of any spalling concrete in your flat”.
HDB has advised homeowners to repair spalling concrete themselves if the affected area is small, or engage a contractor for larger areas before more concrete dislodges and causes injury.
MND has stated that Town Councils are only responsible for maintaining the common property.
We can infer from this that the maintaining the interior of flats and necessary repair works are not the responsibility of Town Councils. However, in instances of spalling caused by leakage in the flat unit above, HDB can mediate or enforce repairs.
While HDB has made clear their position on whom the responsibility lies, HDB also has the following available schemes to assist homeowners:
1) Goodwill Repair Assistance (GRA) Scheme
Under the GRA, HDB assists flat owners in arranging for repair works, and co-pays 50% of the cost of repairs for Singapore Citizen households. The affected flat owners bear the balance 50% of the repair costs, which is capped at $300 per flat. For rental flats, HDB bears the full cost for the repair of spalling concrete.
2) Home Improvement (HIP) Scheme
The HIP helps resolve common maintenance problems of aged 30 year old flats such as spalling concrete and ceiling leaks that arise from wear and tear.
The waiting time for the subsidised rectification work can take months so for severe spalling concrete conditions, homeowners should give due thought to whether they can wait it out due to the safety and injury risks.
Final Thoughts
In a city like Singapore, where the climate is humid and rainy, spalling concrete is an issue that deserves attention. By understanding the causes, taking proactive steps to prevent it, and addressing it promptly when it occurs, you can ensure that your home remains safe, functional, and visually appealing for years to come.
If you suspect spalling in your home, don’t wait—reach out to a professional for an assessment. A little maintenance today can save you a lot of trouble tomorrow. After all , prevention is always better than cure especially when the dangers of a falling concrete landing on you is highly likely!
Got questions or need advice on spalling concrete? Feel free to drop us a message—we’re here to help! Contact Asher Pte Ltd today for a healthier, happier home!
You can also check out our Spalling Concrete Video for a better understanding of how we deal with Spalling Concrete. 😊