A Guide on How to Scratch Render
Scratch render is a brand new wall rendering technique that’s usually used with coloured cement to create a render that’s similar to weathered stone. After brushing off the wall that’s going to be rendered, it will need coating with a scratch coat, then to be given a light scratch using a plasterers scarifier or a scratch coat tool (either bought or homemade) before applying the final coating, which will be flattened and given the final scratch using a scratch nail.
- Clearing the Wall. The first step is clearing the wall of dust and loose bits of concrete or plaster. Give the wall a scrubbing and make sure that the area is totally clean from things like moulds and mildew to prevent pockets of air under the scratch coat, which will be applied first.
- Applying the first scratch coat. The scratch coat is applied after giving it a good brushing. Apply a thin amount all over the wall. The ideal thickness of the coating is at least 2 mm. When applying the coating make sure to really push it into the wall and that there are no spots where the coating is thinner than the rest. Make sure to cover the wall as evenly as you can.
- First Scratch. After applying the scratch coat all over the wall, scratch the wall in an even vertical pattern using a scarifier or scratch tools, which looks like a comb. You can also create your own by making a brush-shaped tool using pieces of wood and nails or screws. After scratching the wall, let the coat adhere to the wall before applying the final coating.
- Applying the Final Coating. Applying the final coating is just the same as applying the scratch coat, but this time apply a thicker amount than the first, because the scratch nail will be scratching off a good amount of the top most layer. The ideal thickness of the final coating is around 10 mm. Make sure that the coating is pushed into the scratch coat and that the wall is coated evenly without any lumpy areas. Let the coating adhere to the wall enough that you won’t leave any impression when you touch it but is soft enough to be scratched by your fingernails.
- Final Scratching. Finally scratch the wall with a scratch nail. Depending on how rough you want the wall to be you can use different types of scratch nails. Scratch the wall in a circular motion and scratch evenly across the wall’s surface. Do not scratch too hard as you might scratch too deep and reveal the base. Use an edge trimming plane to trim the wall’s edges for a finer finish.
For best results, ask your local supplier for the best materials on the market today. Also if you are not sure about something inparticular, or have any other questions, consult a professional immediately before attempting any project on your own.