Impact of Workmanship on Performance of Tiled-Wall Systems

To quantify the impact of tiling workmanship on the performance of tiled facades, the Singapore building authority launched a research project to review and investigate the entire process of external wall tiling. As part of this effort, field investigation and laboratory experiment were conducted. The field investigation was specially featured by conducting in-situ pull-off tests on tiled walls of an 11-year-old building. Evidence was obtained by statistically correlating the bond-strength reduction with various signs of inadequate workmanship. However, the bona fide workmanship impact became confused with the weathering effect. To distinguish the two, tiled specimens were carefully fabricated for laboratory experiments. Before being destructively tested, most of the specimens were subjected to a closed-loop-controlled artificial weathering. These tests revealed that bonding strength plunged as the quality of workmanship declined. Although the weathering effect was quite moderate in the specimens prepared with very good workmanship, the synergistic effect of the weathering together with inadequate workmanship was disastrous.