Plastering and rendering are both the process of covering walls. The main difference between the two is that plastering refers to coating the interior walls, whilst rendering is the coating of exterior walls.
The major difference between plastering and rendering is the strength of the materials used for each, because plaster and render are both made from the same building materials including sand, cement, water and gypsum.
Plaster differs to render as it contains less cement in its composition, as it is used to coat the interior walls and ceilings of buildings, so that they will be smooth and flat for painting or wallpapering.
Plaster must be set and completely dry before walls are painted or decorated. Freshly plastered walls should be left to fully dry for at least one week to a month before painting. You can tell that freshly plastered walls are completely dry when there are no dark patches visible, and a light uniform colour is apparent across all walls. Make sure your home is properly ventilated during the drying stage, open windows and doors to allow for natural ventilation. Be aware that newly plastered walls that dry too quickly are subject to cracking.
Rendering is used to coat exterior surfaces of buildings, and contains a higher percentage of cement within its composition. Rendering is applied to the outside of buildings to not only make it more visually appealing, but also provides waterproofing and fireproofing properties.