The most appropriate kind of lime to be used for rendering is hydrated lime

. Other things could also be added to the rendering mix, such as colour-altering pigments, or additives that aid bonding and drying.

Do you put lime in Render?

Why lime helps make the best mix for rendering

Sometimes you can add some building sand to the mix for the base coat but it shouldn't be your primary sand. It's important not to put more than one part lime to one part cement because hydrated lime won't set on its own, you need the cement to help it set.

What is the best mix for rendering?

A common mix ratio used for rendering is 6 parts sand, 1 part cement and 1 part lime. Any general purpose cement can be used, although the sand should be fine and clean of impurities. Coarser sand is usually used as the base layer and slightly finer sand for the top layer.