After getting the keys to her studio apartment in Punggol in January, Madam Carol Khoo, 61, was looking forward to living in her new place. But it has since been flooded twice by sewage and she cannot imagine living there any longer.
"You don't know when it will happen again," said the part-time security officer, who wants a replacement unit from the Housing Board.
The first incident was in April, while she was on holiday in South Korea. She received a call from the HDB saying that water was seeping from her flat. "I couldn't believe it. I asked, 'Are you sure it's my unit?'" she recalled.
When she returned five days later, she found her 45 sq m flat flooded with dirty water. The cause was later found to be plywood blocking pipes carrying toilet waste. This had caused sewage to overflow from the bathroom drain, she said.
Replying to queries, the HDB said renovation contractors are not allowed to put unwanted materials or debris into the waste pipes.
If a contractor is found to have done so, enforcement action - such as financial penalties and demerit points - can be taken against it, under HDB's Registered Renovation Contractors Scheme.
In general, when the HDB receives reports of choked pipes, it investigates and parties found responsible will have to carry out rectification work and bear the costs.
"However, it is not always possible to identify the source of the debris as it could have moved down from higher floors," it said.
Madam Khoo's contractors cleaned up the April mess. Over the next few months, they replaced the skirting, re-grouted the tiles, repainted the walls and replaced the water-damaged built- in wardrobe.
But on June 23 it happened again. The mess was cleaned up the same day, thus causing less damage. However, for Madam Khoo, enough was enough: "I have a phobia of it happening again."
She hopes the HDB will offer her a replacement unit, adding: "I am really desperate for time."
She has already made plans to sell her old four-room flat, with the second appointment with the buyers being on July 19. The HDB said it was " looking into the resident's request for a replacement flat".
In the latest incident, Madam Khoo said workers found cement and cloth blocking the pipes.
To prevent such incidents from happening in their block, all homeowners should do their part by engaging responsible contractors, said renovation firms.
"As a common practice, all contractors or interior-design firms will remind sub-contractors not to dispose of any hard objects in sewage pipes or floor-trap holes," said Mr Dean Lim, director of Ciseern by Designer Furnishings and treasurer of the Singapore Renovation Contractors and Material Suppliers Association.
Mr Lim Kok Huat, who runs Giro General Construction, said such incidents happen when workers are not properly briefed to wipe cement or plaster off their tools before running them under water.
Mr Ron Foo, director of JSR Design & Renovation, said consumers should engage HDB-certified contractors and, if possible, those with further certifications such as a Building and Construction Authority licence or CaseTrust certification.
"Fly-by-night outfits will neither take the trouble to apply for such accreditation, nor will they be able to get it," he said.