Why do floor tiles suddenly pop up with a loud crack?
A tiled floor is a thin, stiff layer bonded to a screed and slab that move differently with temperature and moisture. When compressive stress builds up and the adhesive bond has already weakened, the tiles relieve the stress by lifting into a ridge, often with an audible crack. MND has attributed tile dislodgement in HDB flats to differential thermal expansion and contraction and the natural deterioration of the tile-to-screed bond, and linked a spike in January 2018 to unusually cold weather and temperature swings.
From the RRD Field Guide, checked against the sources cited in Popped, Hollow and Debonded Tiles in Singapore: Causes, Safety, Repair and Who Pays. General information, not advice for your project.
The fuller picture
Tiles pop or sound hollow when the bond between tile, adhesive and screed fails, usually from thermal movement without movement joints, poor adhesive coverage, an uncured substrate or age. Indoors, the unit owner generally pays after the developer's 12-month defects period. On façades, falling tiles are a public-safety risk handled through the MCST or owner and BCA's Periodic Façade Inspection.
More questions on this topic
- Is a hollow-sounding tile always a defect?
- Who pays for popped tiles in my HDB flat?
- Who pays for popped tiles in a condominium unit?
- Can the developer refuse to fix popped tiles after the defects liability period?
- Are popped façade tiles covered by the Periodic Façade Inspection?
- Can hollow tiles be fixed without removing them?
- How do I stop new tiles from popping?