Case 1
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Good Practices
Design
An understanding of the type of structural frame and the amount of movement that could be experienced is needed. Structural concrete to which the tiles adhere to creeps under dead load and live loads. Movement joints extending through the tiling and substrate should be installed to accommodate stresses due to shrinkage, deflection and moisture. They should be as deep as the tile and adhesive, and filled with a stable sealant such as polyurethane. Structural movement joints in the bed and tiling should be sited immediately over and continuous with structural movement joints in the base. In no circumstance shall it be too narrow to allow free movement.
Recommend surface treatment and protection in accordance with SS 509-2, BS 8221-2 or equivalent.
Ensure proper detailing of window, door, and abutment points where water seepage can occur and
cause delamination. Design movement joints are recommended on the structural concrete in accordance with BS 6093 or equivalent. As early as 1992, the then Public Work Department (PWD) — now Building
and Construction Authority (BCA) — issued a memo discouraging the use of tiles (ceramic and stone
tiles bedded with adhesive) on façades of buildings exceeding 4 storeys.
Construction
The tile bed has to be sufficiently flexible so that it can take the moisture and thermal movement. Cement based with polymer latex or resin based mix are suitable for tiles. The grouting material is normally of the same type as tile bed, compatible tot the tile bed and the tile. As tiles are usually adhered to by means of cement mortar or adhesives, it is important to use suitable material specified by the manufacturer. The tiles shall be fully tested to meet the performance requirements stipulated in the contract before mass installation. A good example of suitable tiles for external tiling is single-fired vitrified tiles. Single-fired vitrified tiles (glazed or unglazed) are especially suited for external walls subject to thermal shock conditions in tropical climates. The ceramic tile can withstand short-term changes in temperature over a range of 0°C to 150°C because of its micro-structural characteristics. Proper procedures of tiling should be strictly followed to ensure good performance of tiling system. Skilled labour and good supervision can enhance the quality of construction. A checklist for onsite tiling inspection can be used.
Sufficiently remove curing agent (used for early stripping of formwork) to ensure proper adhesion on
the substrate. Ensure proper substrate preparation (cleaning) prior to application of plaster/tile finishing. Perform quality workmanship on façade through the correct handling and angle of application to prevent delamination and debonding in accordance with BS 8000-0 or equivalent. Lay adhesive and tiles in the sequence according to the manufacturer’s instructions. Adopt the performance requirements for curtain
wall, including safety in accordance with BS EN 12179, ASTM E2270-14 or equivalent.
