Use of a silicone-based hydrophobic treatment in ceramic floor tiles: a case-study in Portugal

Abstract

Hydrophobic treatments are often used in porous ceramic floor tiles to prevent the occurrence of stains during the use phase. Premature failure of the ceramic pavement of several apartments and townhouses of a golf resort in Portugal occurred between 2006 and 2007. The problem took place three to four years after application. It consisted of tile detachment, which resulted in markedly irregular pavement surfaces. The anomaly affected only those tiles treated with a silicone-based hydrophobization product, regardless of them being located in a ground or upper floor. Similar, but non-hydrophobized tiles, which had been used before in some dwellings, showed no anomalies. This article describes the problem in detail and presents the work carried out to identify its causes. It included site-inspections with collection of samples, as well as thermal (EN ISO 10545-8) and moisture (EN ISO 10545-10) expansion tests. It is concluded that the anomaly was probably due to the confluence of four main factors: (i) presence of moisture in the buildings; (ii) high moisture expansion of the ceramic tiles, (iii) poor application of the tiles; (iv) use of the hydrophobic treatment in these tiles.