The degradation of the “Study room” (Convent of Christ, Tomar, Portugal), from a preliminary analysis towards a sustainable maintenance

Following a comprehensive analysis of the stone degradation of the “Study Room”, in the Crow’s Cloister west wing (Convent of Christ, Tomar, Portugal), a multiapproach plan was made to address the salt problems encountered on its limestone columns. Chemical characterization studies were made to determine the concentration and the type of the efflorescence soluble salts involved, as well as the ionic composition of the limestone material of the column, and also, in which environmental conditions their harmful activity is reduced (or prevented). Finally, on site, the existing cement mortar was removed in a 30 cm area around the base of the column, and the ionic characterization obtained was submitted to the ECOS-RUNSALT software, which determined that simply by fixing the relative humidity at 65±2%, the weathering process would be substantially reduced – conditions different from the ones encountered.