The Housing and Development Board (HDB) is introducing a new waterproofing method for leaky ceilings, which is a common problem in older flats.
The new method will be less invasive than the current one, and uses a polymer solution that is to be applied across the flooring. The solution forms crystals in the cracks in the concrete slabs, acting as barriers that restrict the water from entering.
Current ceiling leak repairs done under the Goodwill Repair Assistance (GRA) scheme requires the removal of the floors and fixtures at the leak area, so that a new layer of non-shrink grout and waterproof membrane can be applied. The fixtures and the floor tiles have to be reinstalled after the works have been done. This method usually takes 3 and a half days to be completed. The new method will take about half a day.
Free trials for this new method are currently being offered to some units that are having water leakage problems. Two units have gone through the trials at the beginning of this month. HDB is using these trials to evaluate the effectiveness of the new method before introducing it to all flats.
Under the GRA, the upper and lower floor units usually share 25% of the repair cost, while HDB covers the other half.26,000 ceiling leakage cases have been reported every year on average, about 2.9% of all HDB flats. 500,000 out the 900,000 HDB units are currently more than 25 years old.
Older HDB flat units are also likely to face problems with spalling concrete, with an average of about 9,000 cases in the last 3 years. This occurs when carbonation causes the steel reinforcement bars within the ceiling slab corrode, causing the concrete cover to crack and bulge. This problem is usually resolved by cleaning the corroded bars and then painting them over with anti-rust paint. Repairing such a problem should be left to qualified contractors to ensure a quality job.