SINGAPORE - There have been 700 cases of popped or dislodged tiles in Housing Board flats in the first half of January alone - a third of the total reported in the whole of 2016.

The HDB received about 2,000 cases every year in the past two years.

Here are some reasons why tiles in flats may pop.

1. WEATHER CHANGES

The differential thermal expansion or contraction of the tiles can result in a loss of adhesion between the tiles and the screed surface over time, said a HDB spokesman.

Significant changes in temperature can also cause "more stress to be built up beneath the tiles and contribute to the loss of adhesion", she added.

2. POOR CONSTRUCTION OR QUALITY

Another reason could be that the cement base of the floor was not mixed properly, so when tiles are laid on top of the cement base, the bonding between them is not complete, said Mr Richard Lam, director of general contractor firm Wellbase Builder.

In other situations, the tiles chosen may be of poor quality, and are more susceptible to breaking.

3. WEAR AND TEAR

Natural deterioration may cause the bond between tiles and the floor's cement surface to come apart over time. Tiles can also swell with high moisture absorption, and due to expansion, the pressure could cause the tiles to pop up, said Mr Jayden Shen of Hua Seng Contractors.

4. WHAT TO DO IF YOUR TILES ARE DISLODGED

Flat owners are responsible for the maintenance of their flats, including repairs for general wear and tear, but the HDB helps owners repair dislodged tiles originally provided by the board during the one-year defect liability period and offers goodwill repairs for dislodged tiles for up to 15 years.

For flats that are older than 15 years, HDB will help carry out inspections and assist the owners to remove and dispose of the affected tiles. Owners can get a list of registered repair contractors from the board, and engage them on a private basis.

Residents can also call the HDB branch hot line on 1800-225-5432 for advice, or the Emergency and Maintenance Services Unit, details of which are listed on lifts at each HDB flat block.