Rendering is the process of applying a sand and cement mix to external walls.
Render can be applied over brickwork, stone and blockwork walls.
Depending on the wall substrate to be rendered, the render coating may be applied in up to three layers: the 'scratch coat', intermediate and top coat. If the substrate is stable and even, two layers maybe more appropriate.
Chemicals (admixtures) may be added to the render mix to modify its properties. For example bonding agents to the base layers and waterproofing admixtures to the final layers.
Rendering of walls is carried out for one or more of the following reasons: to provide a smoooth surface for painting; to help stabilise old brickwork; to provide a waterproof seal against the weather.
Pictured below:
• Hacking off damaged render on a garage wall; cleaning loose material; application of scratch coat/ bonding coat; intermediate layer; application of pebbledash top layer to match existing.
• Removal of loose render from chimney; rendering to help stabilize old brickwork; application of pebbledash.