External house rendering is the basis of every building. Its right choice is an extremely important thing that allows for achieving a number of functions that this layer of the façade is responsible for. Why is worth rendering, and what types of render can we distinguish? Check it out.
Why render external walls is a worthy investment?
Exterior house render perform a number of important functions. First, they are the showcase of every building because they are responsible for the aesthetic presentation of every house, block of flats, or public building. Facade renders also play an important role when it comes to protecting a building from the harmful effects of external factors, such as extremely low and high temperatures or precipitation. The right choice of render helps to ensure optimum protective and insulating properties of the building façade, which is why it is so important that it meets specific requirements and has appropriate technical and operational properties.
What are the different types of house rendering?
Facade renders include a wide range of solutions dedicated to protecting the wall of the building. The basic division, which can be made considering the proposals available on the market, is to
distinguish two basic types of external rendering.
Thin coat renders
They are characterised by rich colours, various textures, and high ease of application. Their application allows obtaining a resistant protective and insulating layer with a thickness ranging from 2 to 10 mm.
Thin layer renders are a very universal solution that can be successfully used both for two-layer walls and exterior walls rendered with traditional thick layer plaster. There are many types of thin coat renders on the market – acrylic, silicone, silicate, and mineral render. However, their price is higher than the price of traditional renders, which is why they are not chosen so often.
Thick coat renders
They are a solution allowing for the laying of facades 20 to 30 mm thick, which is perfect for finishing all concrete walls and masonry walls. Thick-layer plasters include cement, lime, and cement-lime renders. Their price is relatively low, which is why they are a popular choice for a wide variety of applications.
External rendering – what should you consider when choosing the right render?
The choice of an appropriate render for wall covering is an important issue that will translate into the aesthetic appearance of the whole building and proper protection of the external environment against the harmful effects of external factors.
Therefore, while making a decision about the choice of the particular render it is necessary to take into account several factors. The technology of building the house walls and the material they are made of turn out to be important.
When choosing a render, you should also take into account factors such as the conditions of the surroundings, exposure to sunlight, and the location of the house – a different plaster will be recommended for buildings located near a forest, and a different one for the walls of a house erected in a busy street.
Other important factors influencing the choice of the facade plaster are its high durability, resistance to the harmful influence of external factors, and its price – it is worth choosing proven solutions whose price is adequate to their quality. Taking all these factors into consideration allows you to find a high-class external rendering that will help you achieve all the objectives set for the elevation of the building.
Can render be applied over existing render or external wall insulation
Re-rendering a house depends on the condition and type of the existing plaster. Render falling proves that it adheres poorly to the surface, and it should be removed and then filled with a new mass. Before applying a new one over render or external insulation, the old render should be cleaned of dust and other dirt, free from greasy spots and substances that may impair the adhesion of the new render to the substrate.
When selecting new plaster, we have to take into account that its strength is lower than that of the old plaster and water vapour permeability is higher than that of the old plaster. For these reasons, lime and cement plaster can be laid over old cement render, but the reverse operation is very risky.
Similarly, resin renders with a high diffusion resistance should not be laid on old lime or lime-cement plasters. This can lead to the formation of a condensation zone at the border of the two layers, which will cause the plaster to degrade over time.