Decontamination and reuse of tiled surfaces have always been costly activities. This paper describes an investigation into the feasibility of removing cement based grout between commercial tiles using a 1.5 kW high power diode laser (HPDL). It is known that it is very difficult to remove this type of grout conventionally. This investigation involves a single pass laser scan to remove the grout to 3 mm in depth. This paper presents relationships between the laser processing conditions and the material behaviour such as physical changes, thermal profiles after laser treatment and effect of laser processing on the ceramic tiles. A model, based on thermal mapping, was applied to the grout removal process to predict the temperature profiles within the material during the laser treatment. (C) 2003 Elsevier B.V. All rights reserved.