Evaluation of mortar samples obtained from UK houses treated for rising damp

► Mortar samples were obtained from UK dwellings of up to 400 years of age. ► The pH values were found to be in the range of 7-12, with a typical value of 9. ► Sorptivity values were 0.2 to 14 mm min−1/2. ► Older mortars had a higher sorptivity and greater concentration of soluble salts.