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.