Hydrated lime
Short Guide, Lime Mortars in Traditional Buildings, published on 1 March 2013 by Historic Scotland, defines hydrated lime as: ‘Powdered lime formed from the slaking (addition of water) of quicklime. This term may be used in reference to hydraulic limes or air limes, but is typically used for the latter.’
Short Guide: Traditional Scottish Brickwork, published, on 1 March 2014 by Historic Environment Scotland, suggests that hydrated Lime: ‘Commonly used to describe non-hydraulic lime powder which is used in modern cement/lime/sand mortars. It is important to distinguish between this and hydraulic Lime which is the material most commonly used in lime mortar mixes in repair work.’
Society for the Protection of Ancient Buildings (SPAB) definition online Glossary : Hydrated lime or dry hydrate
'Calcium hydroxide (Ca(OH)2) formed as a dry powder when any lime is slaked using an exact amount of water (cf lime putty). Not to be confused with hydraulic lime. It is possible to obtain hydrated hydraulic lime or hydrated non-hydraulic lime.'
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