Roundtower Board Render
Roundtower Board Render is a fibre-reinforced, breathable lime render designed for use over insulation boards within both internal and external wall insulation systems. Formulated using Natural Hydraulic Lime and carefully graded aggregates, it provides a durable, vapour-open basecoat for wood fibre, cork, wood wool, and other breathable insulation boards.
Its combination of strength, flexibility, and vapour permeability makes it particularly suitable for solid wall construction, heritage buildings, and breathable retrofit projects.
Technical Data
| Property | Value |
|---|---|
| Product Type | Fibre Reinforced Lime Board Render |
| Binder | Natural Hydraulic Lime |
| Application | Internal & External |
| Coverage | Approx. 1.5m² per 25kg bag @ 10mm |
| Recommended Thickness | 6–10mm |
| Reinforcement | Alkali Resistant Mesh Required |
| Vapour Behaviour | Breathable & Vapour Open |
| Packaging | 25kg Bags |
Key Benefits
Designed for Insulation Boards
Suitable for:
- Wood fibre boards
- Cork boards
- Wood wool boards
- Calcium silicate boards
- Breathable insulation systems
Breathable & Vapour Open
Allows moisture vapour to move through the wall assembly, supporting the drying potential of breathable construction systems.
Fibre Reinforced
Provides improved crack resistance and durability when used as a reinforced basecoat.
Internal & External Use
Suitable for both internal wall insulation (IWI) and external wall insulation (EWI) systems.
Compatible with Traditional Buildings
Ideal for:
- Solid wall construction
- Heritage buildings
- Stone masonry
- Breathable retrofit projects
Typical Applications
- Wood fibre insulation systems
- Cork insulation systems
- Wood wool board systems
- Internal wall insulation
- External wall insulation
- Heritage renovation
- Breathable solid wall upgrades
Why Use Roundtower Board Render?
Roundtower Board Render provides a durable reinforced basecoat while maintaining the vapour permeability required for breathable wall construction.
It is specifically designed to work with natural insulation systems, helping create robust, moisture-managing wall assemblies without relying on cement-based renders.
Installation Overview
1. Board Installation
Fix insulation boards securely in accordance with the board manufacturer's guidance.
2. Basecoat Application
Apply Roundtower Board Render evenly across the surface.
3. Mesh Reinforcement
Embed alkali-resistant mesh into the wet render layer.
4. Finishing
Once cured, apply a suitable breathable finish coat.
5. Protection & Curing
Protect fresh render from:
- Frost
- Heavy rain
- Rapid drying
- Direct sunlight
6. Storage
Store dry and protected from moisture prior to use.
