What is plaster?
Plastering refers to covering walls and ceilings in houses for both decorative and protective reasons. Plaster which is the major material that is used in plastering is majorly made up of cement or lime or gypsum. Plaster is most likely to come in a powdery form before it is mixed with water or other liquid solutions before it is applied to walls and ceilings. When water mixes with the powdery form, crystallization happens which liberate heat. Then the paste hardens. It is important to know that plaster in itself is not a strong material and it is not capable of bearing load. It is however only decorative or protective and needs a framework from another material to bear it.
There are however different methods and techniques in plastering that might be very important to know and understand. The first method in plastering is skimming. Skimming is often interchangeably used with plastering. However, the difference between skimming and plastering is that while plastering is more general in meaning, skimming is more or less a more specific aspect of plastering. Skimming means using finishing plaster on a new plasterboard or on old, existing walls and ceilings. Skimming might be done to either give a new look to a plastered surface or done to repair or patch up an area of damaged or broken plastered surface.
The second type of plastering is rendering. There is a slight difference between plastering and rendering. Plastering is more of interior application of plaster while rendering is more often done on exterior surfaces. Basically, the combination and types of materials are the main difference between plastering and rendering. The materials are broadly the same, sand, water and sometimes lime. However, when rendering, coarser and higher amount of sand is employed. On the other hand, finer sand is mostly used for plastering to achieve smoother and finer finishing.
What Is Plasterboard?
Another important method to plastering is the actual plasterboarding. Plasterboard is made up of two layers of lining paper with a layer of gypsum inserted in the middle. As mentioned earlier, gypsum is often used to make some types of plaster. The Gypsum within the plasterboard has crystals that contain small amounts of water and is known as water crystallization. If and when there is an outbreak of fire, the water in the gypsum runs off and brings down the temperature and stops the fire from speedily spreading. This attribute of plasterboard can be very essential for homes as it can be used to cut down the outbreak of fire and can also cut down on noise as some high-performance plasterboard can effectively shut out airborne noise like music, voices etc.
Dry lining is basically a method of plastering that involves attaching a plasterboard to a wall, making it easy to start decorating immediately and is quite preferable compared to having to work with wet plaster. A method like dry lining is also considered as a better alternative compared to having to re-plastering a wall or ceiling. With that being said, plasterers have been known to put on a thin coat after dry lining to give it a good finish.
Lime plaster which is a technique of plaster that is mostly made up of sand, water and lime. The lime is most times non-hydraulic lime that is also high calcium and air lime. Lime plaster is usually employed to be quite durable but at the same time, be relatively flexible. It can be a very important part of the construction of a structure. Most of the time you will see lime plaster in older buildings. The most common commercial place will be around a fireplace in an old pub.
Another technique in plastering is floor screeding. Floor screeding is simply the process of building subfloors with cement and other materials for a final finished floor. Floor screeding holds a number of great purposes. The first property floor screeding has is it puts a layer of material over the existing floor and when done properly will preserve and strengthen the floor. The second property is that screeding is a very good self-level. It is common to see a thin coat of self-level screed being used to help level out any rooms. These rooms may have become unlevel over time due to movement of the property.