Do environmental conditions determine whether salt driven decay leads to powdering or flaking in historic Reigate Stone masonry at the Tower of London?

In order to evaluate the potential for using environmental controls as a preventive conservation strategy Reigate Stone masonry, this paper tests hypothesis that powdering and flaking decay patterns are direct consequence of climatic variables. Samples masonry affected by each pattern analysed soluble salt content ion chromatography. The results used build thermodynamic models in ECOS Runsalt. These identify NaCl NaNO3 crystallisation both environments, with dominating masonry. Freshly quarried samples range physical characteristics contaminated mixture these salts. Replicates sample subjected two distinct accelerated ageing regimes. regimes based on monitoring designed reproduce observed pathways. One set is subject partial immersion relatively stable, high RH, stimulate zone near surface. replicate occasional wetting frequent drops within fabric stone. provide some indication intended mechanisms were achieved, supporting hypothesis; however, variation stone was far greater control rate emergence distinctive phenomena. This extended mineralogical composition pre-existing features, such crusts cracks. implication cannot be explained solely mechanisms; baseline mineralogy historical contingency can play crucial role. Whilst may cases, it likely detailed assessment case specifics will necessary.