Roughcast [SEP] material used
Roughcast
Roughcast or pebbledash is a coarse plaster surface used on outside walls that consists of lime and sometimes cement mixed with sand, small gravel, and often pebbles or shells. The materials are mixed into a slurry and are then thrown at the working surface with a trowel or scoop. The idea is to maintain an even spread, free from lumps, ridges or runs and without missing any background. 
Roughcasting incorporates the stones in the mix, whereas pebbledashing adds them on top.
According to the "Encyclopædia Britannica
and curling can be reduced by dividing the area to be covered into smaller sections and then pouring the material. Debonding of the granolithic material can also be significantly avoided by using bonding agents like epoxy resins or polymer latex.
A high degree of skill in pouring and finishing the material is needed to prevent problems. Sealers and hardeners can be added to the granolithic material to improve its resistance to wear.
See also.
- roughcast (pebbledash): visually somewhat similar, but used mostly on outer walls
Bibliography