Roughcasting, also known as pebbledash or harling, is a popular exterior wall finish used in residential and commercial buildings. This technique involves applying a mixture of cement, lime, sand, small stones, and water onto walls to create a durable, textured surface. Roughcasting not only enhances the aesthetic appeal of buildings but also provides excellent weather resistance, making it a favored choice in regions with harsh climates.
Benefits of Roughcasting
- Weather Resistance – Roughcasting creates a protective layer that shields walls from wind, rain, and frost, reducing the risk of water infiltration and dampness.
- Durability – The mixture used in roughcasting is long-lasting and requires minimal maintenance compared to smooth plaster finishes.
- Aesthetic Appeal – Available in various textures and colors, roughcasting allows homeowners to achieve a unique, rustic look.
- Energy Efficiency – Roughcast walls improve insulation, helping to maintain indoor temperatures and potentially lowering energy bills.
- Cost-Effective – Compared to other external wall finishes, roughcasting is an affordable option that offers significant long-term savings.
Roughcasting Process
Surface Preparation – The wall is cleaned and prepped to ensure proper adhesion.
Application of Base Coat – A layer of cement and sand is applied to provide a solid foundation.
Roughcast Mixture Application – The roughcast mix is thrown or sprayed onto the wall, creating the signature textured appearance.
Finishing Touches – Once the roughcast has dried, optional color pigments or sealants can be added to enhance appearance and longevity.
Types of Roughcasting
Traditional Lime Harling – A breathable finish often used for historic buildings.
Pebbledash – A roughcast finish with embedded pebbles or gravel, commonly seen on older homes.
Dry Dash – The stones are applied separately to the wet mortar for a more uniform finish.
Wet Dash – The mixture is pre-mixed before application, creating a smoother yet textured surface.
