Rendering is the application of a cement-based material to external and/or internal brick or concrete walls to produce a smooth or specifically textured surface. It’s the base coat laid down, ready for the plastering top coat. It’s one of the oldest traditions in plastering techniques.
Rendering is popular for the outside of buildings to make a surface ready for painting. The difference between plastering and rendering is the type, consistency and proportions of constituents used in the render. Rendering uses a higher quantity of coarse-grade sand and the surface is generally much rougher than the plaster finish. Pebble dashing is a form of rendering often seen on outside walls, for example.