What Lime to Use?
It is important that the most appropriate material for the well-being of the building is chosen. Every situation needs to be carefully assessed in terms of: • softness of stone, brick etc – this should be a major factor in selection; the mortar should always be ‘softer’ than the stone/brick because it is the ‘sacrificial’ element designed to take water away from the main fabric of the building • the environmental conditions – where the environment is very wet (eg sea-defence walls, canal walls) a hydraulic lime is more appropriate because of its ability to set under water • the existing materials; repairing like-with-like will usually provide the most satisfactory solution both aesthetically and technically, but it should not be done without considering the performance of the original materials • the time of year – lime work (like cement) should never be done when the temperature is 5oC and falling; ideally, fat lime work should be done in spring / early summer, otherwise consideration
