Oral Answer by Ministry of National Development on wall cracks in HDB flats

Apr 1, 2019

Ms Joan Pereira: To ask the Minister for National Development (a) what are the usual causes of cracks on the inside and outside of the walls of HDB flats; (b) what measures does the Ministry take to mitigate these causes; and (c) how often are inspections and maintenance works conducted. 

Answer:

Cracks observed on internal and external walls are usually plaster or skim coat cracks. They are primarily caused by the natural expansion and contraction of building materials, vibration from nearby construction works or renovation activities when residents first move in to their flat. They are non-structural and will not affect the structural integrity of the building.

Over the years, HDB has undertaken several steps to reduce the incidence of wall cracks. First, all HDB flats are inspected at the end of construction to ensure that there are no visible cracks on their internal and external walls before they are handed over to residents and Town Councils. Second, HDB’s adoption of precast technology in the mid-1980s has reduced the need for plastering. Instead, skim coats are used, which are less susceptible to cracks. Third, to reduce the occurrence of cracks at joints between pre-cast panels, HDB has also improved the design and detailing of the joints over the years. Finally, new methods of construction such as large panel precast elements and prefabricated prefinished volumetric construction have reduced the number of joints where cracks can occur.

The Member has also asked about the inspection and maintenance of wall cracks. 

a. For cracks on internal walls, during the 1-year Defects Liability Period (DLP) for new flats, flat owners can feedback on cracks observed to their precinct’s Building Service Centre and they will be rectified accordingly. After the 1-year DLP, flat owners are responsible for the inspection and maintenance of the interior of their flats.

b. For cracks on the external walls of HDB blocks, Town Councils are responsible. They conduct regular inspections on the external façade wall and, where necessary, they will engage a Professional Engineer to follow up on any repairs that are required. Nonetheless, to supplement this, HDB conducts annual audit inspections of selected blocks, with a focus on buildings with more facade elements.