Insulated Render
An insulated render system is a multi-layered approach to thermal insulation applied to the exterior of a building. These systems help improve thermal efficiency and enhance energy performance while protecting the building façade. It typically involves the following layers:
- Rigid Insulation: This layer consists of boards or sheets that provide thermal insulation.
- Reinforcing Mesh: Applied over the insulation, this mesh enhances structural integrity.
- Render Base Coat: A layer of base coat material is applied to the mesh.
- Finishing Coat: The final layer is a protective render finish.
Insulated render systems are commonly used for improving thermal efficiency and enhancing energy performance in buildings.
- Insulation: The core component of an insulated render system is the insulation material. Common options include:
- Expanded Polystyrene (EPS): Lightweight and easy to install, EPS slabs are mechanically fixed to the existing wall.
- Mineral Wool Slab: Provides good thermal performance and fire resistance.
- Phenolic Foam Slab: Offers excellent insulation properties.
- Mechanical Fixings: These are used to attach the insulation boards to the wall. They can be made of metal or plastic. To minimize thermal bridging, adhesive-fixed insulation or a track & rail system can be used.
- Mesh Reinforcement: A mesh is applied over the insulation to create a key backing for subsequent layers.
- Render Base Coat: This layer provides a smooth surface for the final finish. It’s typically applied over the mesh.
- Finish Coat: The outermost layer is the decorative render finish.
- Silicone Render: Durable and water-repellent.
- Mineral Render: Breathable and natural-looking.
- Polymer Plain Render: Versatile and available in various colors.
- Polymer Dashing Render: Textured finish with added aggregates.
- Rendabrick: Simulates brickwork appearance.
- Acrylic and Silicate Renders: Different finishes for aesthetic variety.
- EPS (Expanded Polystyrene) System:
- Prepare the Surface: Clean and repair the existing wall surface.
- Fix Insulation Boards: Mechanically fix EPS insulation boards to the wall using appropriate fixings (screws or nails).
- Apply Base Coat: Apply a base coat (usually cement-based) over the insulation boards.
- Install Reinforcement Mesh: Embed a fibreglass mesh into the base coat while it’s still wet.
- Apply Finish Coat: Once the base coat is dry, apply the final decorative render finish (e.g., silicone render, acrylic render).
- Mineral Wool System:
- Surface Preparation: Clean and repair the wall.
- Attach Insulation Slabs: Fix mineral wool slabs to the wall using adhesive or mechanical fixings.
- Base Coat Application: Apply a base coat (cementitious or polymer-based) over the insulation.
- Mesh Reinforcement: Embed a mesh into the base coat.
- Final Render Coat: Apply the chosen render finish (e.g., mineral render, acrylic render).
- Phenolic Foam System:
- Surface Preparation: As with other systems, prepare the wall.
- Fix Phenolic Foam Slabs: Attach phenolic foam slabs using mechanical fixings.
- Base Coat and Mesh: Apply a base coat and embed reinforcement mesh.
- Finish Coat: Apply the desired render finish.
The finish coat in an insulated render system is the outermost layer that provides both aesthetic appeal and protection.
- Types of Finish Coats:
- Silicone Render: Durable, water-repellent, and available in various colors.
- Mineral Render: Breathable and natural-looking.
- Acrylic Render: Versatile and easy to apply.
- Polymer Plain Render: Offers different finishes for aesthetic variety.
- Polymer Dashing Render: Textured finish with added aggregates.
- Rendabrick: Simulates brickwork appearance.
- Application Process:
- After applying the base coat (which provides a smooth surface), the finish coat is applied.
- It can be trowel-applied or sprayed onto the surface.
- The thickness of the finish coat varies based on the system and manufacturer’s recommendations.
- Benefits:
- Weather Resistance: Finish coats protect against rain, UV exposure, and temperature fluctuations.
- Decorative: They enhance the appearance of the building.
- Breathability: Some finishes allow moisture vapour to escape while maintaining water resistance.