Although there are various studies published in the relevant literature on the use of borates in tile production, borax waste has been mainly used in place of feldspar and the results showed that borate migration to the surface was the commonly encountered problem. Previously, the same authors have investigated the possible use of dewatering sieve waste (TSW) of Etibor Kirka Borax Company (Turkey) in combination with a sanitaryware waste in commercial terracotta production in an attempt to achieve improved product properties. In the present study, the same borax waste (TSW) was preferred for use in a commercial wall tile formulation in proportions up to 20% as a partial substitution for Na-feldspar. A total of four formulations was prepared with 0.5, 1, 1.5 and 2 wt.% TSW incorporation and shaped by dry pressing. The obtained samples were single fast-fired at a peak temperature of 1170 degrees C for a total firing time of 30 min (from cold-to-cold) under industrial conditions. According to the results, the addition of TSW appeared to improve liquid phase development with better physical properties compared to those of standard composition for the firing regime involved. The results indicated a prospect for using the waste as a co-flux in wall tile formulations. (c) 2006 Elsevier Ltd. All rights reserved.