Historic Documents in Understanding and Evaluation of Historic Lime Mortars

Abstract

Sophisticated analysing proceedings have been used in the past to assess the composition of hardened mortars. Chemical and mechanical tests combined with microscopic investigations seem to provide all the information required for the design of repair mortars which physically and visually are appropriate for restoration purposes. Lime putty and hydrated lime of varying quality meanwhile are currently available. Nevertheless, the results are not always convincing. The limit of the analysing techniques has become evident in conservation practise. Knowledge of how mortars have been fabricated, mixed, stored and applied is as important as the chemical composition. The authors have therefore collected information on the fabrication, compositions and use of mortars revealed by an examination of written historic sources.