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Abstract: Mortar samples were obtained from a variety of dwellings in the UK with the majority from houses with rising damp. This paper aims to evaluate the mortar attributes and their influence on rising damp. The samples were characterised in the laboratory in terms of pH value and water absorption characteristics and examined using scanning electron microscopy to reveal the microstructure. It was found that the water absorption characteristics varied considerably, with older mortars having a higher sorptivity and higher concentration of soluble salts. The majority of building mortars treated for rising damp in this survey were approximately 100years old and had a typical pH value of 9. A good understanding of the relationship between rising damp and mortar characteristics was developed, which may be practically employed to assess and mitigate rising damp problems. [Copyright &y& Elsevier]

Abstract: This paper briefly reviews the rising damp phenomenon with a discussion of the controlling mechanisms and contributing factors such as capillary effect, water absorption, evaporation and salt formation. It also presents the results of a study on rising damp based upon a practical year-long test. Measurements were made on rising damp on walls made from different mortars and the observations were compared with theoretical models. It was found that mortar characteristics would significantly affect the height of rising damp. It was also observed that there was a strong correlation between rising damp and the Sharp Front Model, and the rate of absorption of water into the mortar was a key factor in determining the height of the rising damp front. In addition, walls with rising damp treatment are warmer than their control counterparts due to a reduction in surface moisture evaporative cooling. [Copyright &y& Elsevier]