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 render fixed to the wall every 1 to 1.5 meters, to keep the render flat and even. There is also a wide variety of premixed renders for different situations. Some have a polymer additive to the traditional cement, lime and sand mix for enhanced water resistance, flexibility and adhesion. Acrylic premixed renders have superior water resistance and strength. They can be used on a wider variety of surfaces than cement render, including concrete, cement blocks, and AAC concrete paneling. With the right preparation, they can be used on smoother surfaces like cement sheeting, new high tech polymer exterior cladding such as