Assessment of building stone decay: a geomorphological approach

Several factors that must influence how one investigates building stone decay have been identified from studies of natural weathering phenomena. Weathering features are invariably polygenic. Weathering processes fall approximately into high frequency/low magnitude events and low frequency/high magnitude events. Weathering is not continuous but episodic. Physical weathering depends upon the balance between the strength of the stone and the magnitude of the stresses to which it is subjected. Weather is concentrated temporally and spatially. A geomorphologically based checklist for the visual assessment of stone decay has the following broad categories, mechanical breakdown, solution, surface alteration and/or deposition, biological action, and human damage or change. There are many factors involved in the mechanical breakdown of stone, not the least of which is its location. -- AATA