Buildings B

Maintenam3.2. lib) Defects in Buildings (continues)(vi)Defective external wall finishes/mosaic tiles/ceramic tiles/stonecladding/curtain wall (continues)Possible CausesThe defects could be due to ageing, structuralmovements, defective workmanship duringinstallation, thermal movement, defective ormissing expansion joints, damage by externalfactors (e.g. falling objects during typhoon),ingress of water into the gap between the finishesor tiles and the structure, etc.•Relevant Section in Chapter 4For repairing the above defects^ please refer to Chapter 4 Section 4.1.1 onwards.* Structural cracks deserve immediate attention. They indicate that the structureof the building, or at least a part of it, is overstressed. A structure, when stressedbeyond its capacity, may collapse without further warning signs. When suchcracks suddenly develop, or appear to widen and/or spread, the findings mustbe reported immediately to the Buildings Department. A building professionalsuch as a Registered Structural Engineer is usually required to investigate the cause(s)of the cracks, to assess their effects on the structure, to propose suitable rectificationand remedial works, and supervise the carrying out of such works.(c)Defects in Building Services InstallationMost of the mechanical components of the building services installationshave a relatively shorter life span than the building structure. Defects inthe mechanical components usually lead to failure requiring repair orservicing. It is therefore necessary to have a planned schedule for foreseeableservicing and replacement for components. Avoid exhausting the designedlife-span of such components can prevent sudden breakdown of servicesthat causes undesirable or even disastrous consequences. For more detaileddescriptions on building services installations and their maintenance, pleaserefer to Chapter 4 Section 4.1 .2. Common defects in building servicesinstallations are summarized as follows:UNDERSTANDING BUILDINGMAINTENANCE & MANAGEMENT