Over a while all external walls of a structure do undergo severe wear and tear, after being exposed to extreme weather conditions, ranging from hot to hotter during some part of the year, cold to coldest during another part, and damp, humid and wet during the balance part of the year. It would be best if you had house rendering and rendering of walls, as the mixture of sand, primer and cement coating can add a new lease of life to your exterior walls. Cement rendering is generally textured, colored or painted after application and is usually used on the exterior and interior walls of the house.
Coarse and fine application, depending on your requirement:
Based on the look required, the application ranges from fine to coarse, smooth to textured, natural to colored, plain to blended and painted to pigment. Using cement rendering to brick, concrete and mud houses has been in vogue for centuries together to improve the appearance and at times offer weather resistance to exterior walls. Proper render styles and finishes can add a more decorative touch to the interior and exterior of your house.
Cement is mainly used as a binder, a substance that both alone and also mixed with other materials together, sets and hardens.
Different finishes are created by professionals using various tools such as picks, trowels, brushes, sponges or rollers. Getting a perfect mix and traditionally rendering the topcoat are by themselves, art forms.
There are two forms of house rendering in practice today:
a) Traditional rendering
b) Acrylic rendering
These are basically to suit specific end-user requirements. Acrylic rendering has a polymer additive mixed to the traditional mix of cement, lime, and sand to offer enhanced water resistance, adhesion and flexibility.
There is also a wide variety of premixed renders for different situations. Some have a polymer additive to the traditional cement, lime and sand mix for enhanced water resistance, strength, adhesion, and flexibility.
When used with the correct preparation, they are used on smoother surfaces like expanded polystyrene, the latest high-tech polymer-coated sheets, and the traditional cement sheets.
How is cement house rendering done?
Cement rendering is a mixture of 6 measures of fine sand, one measure cement, and one measure lime. Lime in the mix makes the render more amenable and reduces the possibility to crack after it dries. Any quality of cement could be used in this mix.
Coarse sand is used for the base layer, while very fine sand is used for the top layer. In a traditional rendering, usually, three coats are applied, i.e. the first coat of cement render using coarse sand. Before the application of a second layer in the same fashion, a wire mesh is fixed on top of the first coat to ensure that the plaster does not crack up or become weak.
The second layer is applied on top of the wire mesh. A smooth, white finish coat goes on last. After the plaster is completely dry, the walls are ready to be painted in attractive colors.
To make the whole process of cement rendering look more artistic before the final finishing touches, a coating of gypsum (also known as Plaster of Paris) is used. When water is mixed with dry plaster powder, it turns into gypsum. The unmodified plaster starts to set about ten minutes after the final mixing and is thoroughly done in about 45 minutes.
Cement house rendering is usually applied to masonry walls on the interior and exterior walls to achieve a smooth surface. A final layer of gypsum plaster is sometimes applied to interior surfaces. These primarily form the light range of plasters. Massive versions of similar plasters are used for fireproofing, vessel skirts, to protect liquefied petroleum gas vessels and pipelines.