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
Cement or under water and further protects the hardened material from chemical attack. The chemical process for hydraulic cement found by ancient Romans used volcanic ash (pozzolana) with added lime (calcium oxide). The word "cement" can be traced back to the Roman term "opus caementicium", used to describe masonry resembling modern concrete that was made from crushed rock with burnt lime as binder. The volcanic ash and pulverized brick supplements that were added to the burnt lime, to obtain a hydraulic binder, were later referred to as "cementum", "cimentum", "cäment", and "cement". In modern times, organic polymers are sometimes used as