SINGAPORE — On the day that contractors started hacking at the roof of Tan's Housing Board block in Jalan Tenaga in October, a roughly 2m-long crack appeared on the ceiling of his top-floor unit.

The crack opened right above the spot in his bedroom where the retired policeman would lay his head when he went to sleep each night.

Tan, who declined to give his full name, told The Straits Times in Mandarin: "I worry that if the crack gets worse, the ceiling could suddenly drop on me when I'm in bed."

The hacking is part of reroofing works that are being done at the 17 blocks in the Jalan Tenaga estate in Bedok.

Tan is one of at least four households living on the top floor of this estate near Bedok Reservoir that have noticed cracks in their flats after the works started two to three months ago.

The 75-year-old, who lives in the flat with his wife, reported the crack in his bedroom to the town council in October, prompting it to send a representative to his four-room executive apartment to take photos of the damaged area.

"The town council sent someone down to take photos again, and said they will come and fix things once the reroofing works are done," said Tan.

"I'm quite confident they will resolve the issue, but for now, we just have to hope the cracks do not get more serious."

A notice at the lift lobby of Tan's block said the reroofing works — which typically involve hacking off the surface of the roof and replacing it with a new waterproofing membrane — are expected to be completed by Dec 13 for the block.

Notices at other blocks said reroofing works at those blocks began in September. The blocks in the estate were built between 1992 and 1993.

Town councils are responsible for the maintenance of common property in HDB estates, including rooftops of public housing blocks.

Another resident, who wanted to be known only as Wee, said leaks from an existing crack in his bedroom toilet have worsened in recent months.

He also noticed new patches of mould in his kitchen and study, where a hairline crack has appeared above the air-conditioner.

The 39-year-old scientist said: "The leaks in the toilet happen on and off. Each time, the ceiling would stop leaking for a while after I report it to the town council, which would tell me they will rectify some issues on the roof, and then the leaks will resume a few months later.

"But this time, the leaks are even worse, and I have to get a pail to catch the water and replace it every day. I don't know if it's because of the reroofing works, the recent rainy weather, or both."

Singapore recorded its wettest November in 2024 since rainfall data collection began in 1980, mainly due to frequent downpours brought on by the north-east monsoon season.

Wee, who said the large crack in his toilet had emerged shortly after he moved into his flat four years ago, added that he is worried the mould in other parts of his flat will affect the health of his three-year-old son.

On why he had put up with the crack for four years, Wee said he wanted the town council to first resolve potential issues with the roof, as any interior fix will otherwise be for nought.

A resident of another block, Huang, 64, said she is concerned about the structural integrity of her executive apartment, after more than a dozen cracks appeared on the walls and ceiling from October.

"It looks like there was a mini-earthquake here, and it's as if something could collapse at any time," said Huang, who has lived in the flat with her husband for more than 30 years.

She said the Aljunied-Hougang Town Council's project manager told her they can plaster and paint over the cracks, but Huang does not think that is sufficient, especially as there are multiple cracks in her false ceiling.

The Straits Times showed photos of the cracks to Lu Jin Ping, president of the Singapore chapter of the American Concrete Institute, who said there was a possibility that they were signs of a structural issue. The institute is a non-profit that organises events and courses to promote best practises in the design, construction, manufacture and maintenance of concrete products and structures.

"It seems that there was some structural movement that has caused these cracks because they are longer than usual cases of spalling concrete, and they start from the corners," he said.

"Some of the cracks also extend at a 45-degree angle from the corners, which means that it could be a structural issue."

He added that a professional engineer should inspect the affected flats to see how deep the cracks are, and for damage to the concrete. This would require removing false ceilings.

As for residents' reports of leaks, Lu said water leaking from an exterior wall into a flat's interior can cause corrosion and weaken its structure over time.

ST has asked HDB whether the agency is assessing the structural integrity of the buildings.

In response to queries, the Aljunied-Hougang Town Council said the reroofing works in Jalan Tenaga are part of works that must be done every 14 years, and they are expected to be completed by the second quarter of 2025, subject to weather conditions.

The town council said it has visited households that have reported cracks and leaks, and will arrange repair works for them.

"Feedback of such nature is not uncommon, and reroofing helps to address the issue of ceiling leaks," said a town council spokesperson.

"The town council will also work closely with HDB, should residents raise concerns on the structural integrity of the flat."

This article was first published in The Straits Times. Permission required for reproduction.