The owners of Rivervale Mall in Sengkang have been ordered to carry out rectification works after cracks appeared on the mall's facade.

The Building and Construction Authority (BCA), responding to queries from The Straits Times yesterday, said it made the directive after sending an engineer to investigate the matter.

It added that while the structural integrity of the mall is not affected, the area below the building has been cordoned off as a precautionary measure.

A spokesman for the authority said it was alerted to a social media post that showed cracks measuring roughly 4m down the side of the top section of the mall's facade.

The engineer found that apart from the damaged facade wall, the cracks in the wall had been patched up before.

BCA said the building owners have been asked to hire a professional engineer to investigate the damage. It also recommended that the owners carry out repair works to fix the wall once and for all.

Meanwhile, in Bukit Batok East Avenue 5, large cracks formed along a footpath near Little Guilin in Bukit Batok Town Park.

A slab of concrete shielding a bank appeared to have dislodged, obstructing the pavement, which has been cordoned off.

In an Instagram post yesterday, Ms Low Yen Ling, an MP for Chua Chu Kang GRC and chairman of its town council, advised those in the vicinity to take extra care, especially during wet weather, noting the heavy rain over the past few days.

She added that investigations by the National Parks Board were under way and that it was keeping an eye on the condition of roads and parks in the estate.

Singapore experienced record rainfall over the past few days, with more rain falling over parts of the country than any other day in August since 1983, according to the National Environment Agency (NEA).

The western area of Singapore recorded the highest rainfall on Tuesday morning.

Between 7.50am and 10.50am, said national water agency PUB, a rainfall station at Bukit Panjang Road recorded 159.8mm of rain, which is more than the country's average monthly rainfall in all of August to date.

On Sunday morning, a 40m-long block of concrete collapsed from four storeys high at an industrial building at 3013 Bedok Industrial Park E. No one was injured.

JTC Corporation was asked by the BCA to inspect three adjacent blocks with a similar concrete sunshade design. The Straits Times understands that rectification and efforts to clear the debris are still in progress.

The heavy rain also caused multiple flash floods across the island this month.

On Tuesday, cars were stuck in water as floods along Dunearn Road made it impassable. Commuters were urged to avoid areas in the northern and western parts of Singapore where water levels in drains and canals had reached 90 per cent.

Flood water even crept into Bukit Timah Plaza, damaging goods and causing shoppers to trudge through large puddles.

NEA said the heavy rainfall over the last few days was due to the convergence of winds over Singapore and warned that thundery showers can be expected to continue over the next few days.