Roundtower Wood Lath Render
Roundtower Wood Lath Render is a high-performance, fibre-reinforced basecoat render specifically designed for use on traditional timber lath systems. Formulated using NHL 2, high-purity CL90 hydrated lime, Vicat Prompt Natural Cement, graded natural sands, and reinforcing fibres, it provides excellent adhesion to timber laths while maintaining the breathability and flexibility required for traditional lime plaster systems.
Its rapid-setting formulation helps reduce the risk of slump, cracking, and delamination, making it particularly suitable for conservation projects, traditional ceilings, partition walls, and heritage plaster repairs.
Technical Data
| Property | Value |
|---|---|
| Product Type | Fibre-Reinforced Lime Basecoat Render |
| Binder | NHL 2 + CL90 Hydrated Lime + Prompt Natural Cement |
| Aggregate | Coarse Kiln-Dried Sand |
| Application | Walls & Ceilings on Timber Lath |
| Yield | Approx. 13–14 Litres per 25kg Bag |
| Water Addition | 4–5 Litres per 25kg Bag |
| Setting Time | Approx. 40–90 Minutes (Temperature Dependent) |
| Colour | Natural Tan |
| Packaging | 25kg Bags |
| Vapour Behaviour | Breathable & Vapour Open |
Key Benefits
Designed for Timber Lath
Specifically formulated to provide a strong mechanical key into traditional vertical and horizontal timber lath systems.
Rapid Set Formulation
The addition of Prompt Natural Cement promotes an early set, helping reduce the risk of:
- slump,
- cracking,
- and delamination.
Breathable & Vapour Open
Maintains the vapour permeability required for traditional solid-wall buildings and lime plaster systems.
Flexible & Low Strength
Developed to provide the flexibility and lower strength required when working with timber laths and traditional construction methods.
Fibre Reinforced
Contains reinforcing fibres and selected additives to improve the mortar's physical and mechanical properties while maintaining compatibility with traditional building materials.
Typical Applications
- Timber lath ceilings
- Timber lath walls
- Heritage plaster repairs
- Conservation projects
- Traditional lime plaster systems
- Georgian and Victorian restoration
- Timber frame buildings
- Breathable renovation projects
Why Use Roundtower Wood Lath Render?
Traditional timber lath systems require a basecoat that can achieve an effective mechanical key while remaining breathable and flexible enough to accommodate movement within the timber background.
Roundtower Wood Lath Render has been specifically developed for this purpose, combining the workability of lime with the early set provided by Prompt Natural Cement. The result is a durable, breathable basecoat suitable for traditional plastering applications on both walls and ceilings.
Installation Overview
1. Surface Preparation
Ensure laths are securely fixed and free from dust, debris, and loose material. Dampening may be required depending on background conditions.
2. Mixing
Add approximately 4–5 litres of clean water per 25kg bag and mix thoroughly for a minimum of 5 minutes.
3. Application
Apply directly onto timber laths as a basecoat render, ensuring adequate key formation through the laths.
4. Finishing
Suitable as a backing coat for subsequent lime plaster or lime finish coats.
5. Storage
Store dry, off the ground, and protected from moisture. Use within the manufacturer's recommended storage period.
