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
Sorel cement flour, asbestos, wood particles and expanded clays. Sorel cement is incompatible with steel reinforcement because the presence of chloride ions in the pore solution and the low alkalinity (pH < 9) of the cement promote steel corrosion. However, the low alkalinity makes it more compatible with glass fiber reinforcement. It is also better than Portland cement as a binder for wood composites, since its setting is not affected by the lignin and other wood chemicals. The resistance of the cement to water can be improved with the use of additives such as phosphoric acid, soluble phosphates, fly ash, or silica.