Rendering is a very broad term in the the plastering industry. It generally refers to the covering of an erected wall or surface with a cement mixture. We use this term a lot more when speaking of external walls. It is a more cement-rich mixture than what we would use inside and is designed to withstand the elements. It is increasingly common, especially in modern architecture to render entirely the outside of a house.
Once rendered and carefully finished and ruled, the surface will be perfectly flat and all corners will rest as perfect right angles. The rendered surface, if not sand finished is then ready to be sealed in an acrylic render (texture coat).
Rendering a home or building is a good way to modernise the property, increase its value and even provide a degree of insulation in those cooler months, while keeping the place a little cooler on those hot summer days.
On internal walls, we use less the terminology, rendering. We actually use a less cement-rich mixture and interal walls are finished in a white set plaster. We call this process internal setting or float and set.
Float and set in the simplest of terms refers to the two layers of cement and plaster which generally finish internal walls of a house or building. It leaves the inside walls smooth to the touch, and ready to be painted. Float, another term for render is a sand and cement compound. It is applied directly to a variety of bases – commonly brick walls to straighten them and provide a flat area on which to apply a coat of plaster (setting). White set plaster (set), is the outermost layer of an internal wall – applied to the float. It is a mixture of lime putty and hardwall plaster. It can also applied to concrete ceilings.