What is and why should I protect my house with roughcast?
Rough casting is an exterior coating on the outside walls of a house, which is sometimes referred to as pebble dash or render. First line of protection against the elements.
Traditional render systems
Traditional methods of roughcast are sand and cement mixture, mixed in a cement mixer, and applied by hand (Trowel) Using 2 coats or layers.
First coat (8mm – 10mm thick) commonly known as the scratch coat, where once applied to the wall evenly, it is scratched with a tool to leave lines on the surface to witch the second coat will adhere to.
The second coat or top coat (also 8mm – 10mm thick) is then applied by hand, evenly as possible and the chips or shells are then cast on, adhering to the top coat.
Colour choice can be quite limited. Colour is added by using coloured sand on top of either white or grey cement. This results in the choice of grey, cream, brown or white.
Modern render systems
Modern render systems are more lightweight. These can be applied by hand with a trowel again, or by a machine, using a spray. These are more U.V stable, with better U values for insulation.
Unlike the old system, we do not need to create the colour with sand and cement. The manufacturer colours this for us. For this system only water is required.
Colour choice is vast with this system. You can chose from around 50 different colours. Any patching or repairs needed for accidental damage down the line can be done with a better colour match because this system is more U.V stable.
This system is far better than the traditional method, when being applied as an overcast i.e on top of existing roughcast that is not or can’t be removed.