Observations of three-dimensional salt distribution in building sandstone

Observations of three-dimensional salt distributions within three sandstone blocks after 120 years of exposure in an aggressive urban environment are presented, based on measurements of soluble ion concentrations. Results indicate a complex distribution of sulphur and chloride, where distributions are not consistent between salt types, dictated by conditions at the six surfaces of the blocks. This highlights the dangers of extrapolating the results of salt weathering simulations with regard to salt accumulation patterns, or the results of fieldwork which rely on single-surface samples from individual stones. The widely held perception that urban environments are 'dry' with shallow surface wetting of building stone does not appear to hold true for certain building stone. Copyright (C) 2000 John Wiley and Sons, Ltd.