Last week's case of falling concrete pieces in a Yishun HDB flat injuring an 80-year-old man may have been dramatic. But it was not an isolated one.
In the last three years, about 17,800 households received help from the Housing Board to deal with spalling concrete - concrete that has broken up or flaked - under an assistance scheme.
The Goodwill Repair Assistance (GRA) scheme, started in 2001, allows flat owners to ask for assistance via their grassroots advisers. HDB and the home owner split equally the cost of repairs for ceiling leaks and spalling concrete.
HDB was unable to reply by press time on the total number of spalling concrete cases. But in 2012, then Minister of State for National Development Lee Yi Shyan said the problem afflicts about 1 per cent of all flats and 2 per cent of older ones built between 1983 and 1986.
Spalling concrete occurs when steel bars embedded in the ceiling start corroding, causing the concrete to crack and fall off in chunks.
How to prevent spalling concrete
PAINT CEILINGS REGULARLY
The carbonation process, which causes spalling concrete, can be slowed down or prevented by painting the ceiling regularly.
Residents should paint their ceilings every three to five years, using a few coats of anti- carbonation or good quality paint.
SEAL CRACKS AND HOLES PROPERLY
If there are holes drilled in ceilings that are no longer needed, seal them immediately. This helps to prevent moisture and carbon dioxide from entering the concrete. Cracks on the ceiling should be sealed as and when they appear.
PROVIDE SUFFICIENT VENTILATION
A humid environment speeds up the carbonation. Humidity levels can be kept down in moisture-prone areas, like the kitchen and bathrooms, by opening vents, windows and doors.
It usually occurs in older buildings and is particularly problematic in bathrooms, as moisture causes the steel parts to rust. Experts have said spalling concrete poses no risks to structural integrity unless it is neglected, allowing it to spread.
Block 141 Yishun Ring Road, where last Friday's incident occurred, is 32 years old and has not undergone upgrading under HDB's Home Improvement Programme.
Yesterday, the flat owner, a 50-year-old part-time accountant who wanted to be known only as Ms Gan, told The Straits Times that her father, who suffered surface lacerations on his leg, is recovering.
She added that HDB officers said they would visit to conduct a more detailed check on Saturday, and she has agreed to take up the GRA offer.
She said she noticed a long crack appearing in her bathroom a few months ago, but thought she could live with it. But after her father made the news, Ms Gan added: "I think Singaporeans will be more aware of such a problem now."
HDB says flat interiors are the responsibility of home owners. It tries to spread awareness of home maintenance through free talks, which the public can register for online. It also has a page on how to treat spalling concrete on its website.
But MPs yesterday told The Straits Times it would be ideal if HDB could conduct routine checks, especially at flats with elderly members. They acknowledged that this would be a resource-intensive exercise.
Ms Tin Pei Ling, MP for the ageing ward of MacPherson, suggested stepping up public education efforts with brochures and roadshows.
Nee Soon GRC MP Lee Bee Wah, an engineer, said residents are best placed to notice wear and tear, saying: "The moment you see a crack on your ceiling, do something."
Repairs cost about $300 for spalling concrete in an area the size of a cellphone, to $1,200 for the entire ceiling of an HDB toilet, said Mr Ravits Goh, managing director at A & R Construction and Engineering, an HDB-approved contractor. Most cases his firm has seen are in blocks that are about 20 to 30 years old.
One home owner who has taken matters into her own hands is piano teacher Catherine Lim, 54, who lives in a 36-year-old block in Clementi Avenue 4. After some plaster debris fell on her bathroom floor two years ago, she and her husband bought a can of paint, grabbed a ladder and patched the hole.
Shrugging off the effort, she said: "It's part and parcel of living in an old house. You can't blame HDB for everything."