Rendering is a four step process in order to cover external walls of a building, however all four steps are not always needed. It is desirable for a number of reasons. These may include filling and covering gaps in brickwork, which could eventually contribute to structural damage to the property, and also updating the look of a property, replacing tired old brickwork or previous render with a fresh new finish.
The first step in rendering is to prepare the surface of the wall. We will strip off all existing render if neccessary to ensure a good adhesion to the wall. Any deep gaps or holes are filled in, and then a PVA mixture is applied to the wall.
The second step is to apply an undercoat of render to the wall, also known as the scratch-coat. The render is made from a sand-cement mixture made on site. We also add a waterproof additive, this stops water reaching behind the render eventually causing cracking and separation from the wall. The undercoat is scratched to increase surface area for the top coat and maximise adhesion.
After the scratch-coat has dried usually taking a couple of days, a smooth top-coat is applied. This is floated and then trowled to leave a smooth finish.
The final step is to apply a finish to the dried render. The top-coat will be flat and smooth but will always have small imperfections due the material. There are a variety of finishes available depending on personal choice. We can offer both oil based finishes and gypsum based finishes such as tyrolean. In most cases the finish does not need to be painted. Please ask us for advice.
