Lime mortar lime putty when mixed at a 1 to 3 ratio, fill these voids to create a compact mortar. Analysis of mortar samples from historic buildings typically indicates a higher ratio of around 1 part lime to 2 part aggregate/sand was commonly used. A traditional coarse plaster mix also had horse hair added for reinforcing and control of shrinkage, important when plastering to wooden laths and for base (or dubbing) coats onto uneven surfaces such as stone walls where the mortar is often applied in thicker coats to compensate for the irregular surface levels. If shrinkage and cracking of the lime
Hydraulic lime Hydraulic lime Hydraulic lime (HL) is a general term for varieties of lime (calcium oxide), or slaked lime (calcium hydroxide), used to make lime mortar which set through hydration. These contrast with varieties of "air lime", the other common types of lime mortar, which set through carbonation (re-absorbing carbon dioxide (CO) from the air). Hydraulic lime provides a faster initial set and higher compressive strength than air lime and "eminently hydraulic lime" will set in more extreme conditions including under water. The terms "hydraulic lime" and "hydrated lime" are quite similar and may be confused but are not necessarily the