- What is Wood Fibre?
- 1. Installing Wood Fibre Insulation Boards
- 2. Installing Screw Fixings
- 3. Applying EWI-748 Lime Basecoat
- 4. Embedding the Fibreglass Mesh
- 5. Applying a Second Coat of EWI-748 Lime Basecoat
- 6. Applying EWI-749 Fine Finish Lime Plaster
- 7. Applying EWI-705 Lime Paint
- 8. Optional EWI-707 Lime Wash
- 9. Why Choose a Lime onto Wood Fibre System?
What is Wood Fibre?
Wood fibre is a natural insulation material used in external wall insulation systems where breathability, moisture management and sustainability are important. It is particularly well suited to older properties, solid wall homes and renovation projects where allowing the wall to breathe is essential.
Made from natural wood fibres, these insulation boards offer strong thermal performance, good acoustic insulation and excellent vapour permeability. This means they allow moisture vapour to move through the wall build-up, helping to reduce the risk of trapped moisture and condensation.
When paired with lime-based basecoats and finishes, wood fibre forms part of a highly breathable system that is flexible, durable and well suited to traditional and heritage-style properties.
This type of system is ideal for projects that require a more natural alternative to conventional render systems, while still providing an attractive and long-lasting external finish.
We have created a handy buyers guide to help you understand the wood fibre insulation installation process and the components required for a lime-based external wall insulation system.
1. Installing Wood Fibre Insulation Boards
The first step in the system is to install the Wood Fibre insulation boards onto the prepared substrate.
Wood fibre boards are a natural insulation material that offer strong thermal performance while remaining highly breathable. This makes them ideal for use within lime-based systems, where vapour permeability is a key part of the overall wall build-up.
As well as helping improve the thermal efficiency of the building, wood fibre also offers acoustic benefits and contributes towards a more natural and sustainable construction approach.
The boards should be fitted carefully to create a flat and even surface, ready for mechanical fixing and the following coat applications.
2. Installing Screw Fixings
Once the wood fibre boards are in position, they should be secured using suitable screw fixings.
Mechanical fixing is an important part of the system, helping to ensure the boards remain securely held in place over the long term. The correct fixing type and length will depend on the substrate and insulation thickness being used.
Fixings should be installed evenly across the boards in line with the project specification, ensuring the insulation is firmly anchored back to the wall.
This step is essential for creating a stable base for the lime basecoat and finish layers that follow.
3. Applying EWI-748 Lime Basecoat
After the wood fibre boards have been fixed, the next step is to apply EWI-748 Lime Basecoat.
This basecoat is designed to work as the reinforcing layer within the system, providing a breathable and durable surface over the insulation boards. It helps level the surface and creates the first protective coat within the lime build-up.
Lime basecoats are especially well suited to breathable wall systems because they allow vapour to pass through, rather than trapping moisture within the structure. This is one of the main reasons why lime and wood fibre work so well together.
The basecoat should be applied evenly across the face of the insulation boards, ready for the mesh reinforcement layer to be embedded.
4. Embedding the Fibreglass Mesh
While the EWI-748 Lime Basecoat is still wet, Fibreglass Mesh should be embedded into the basecoat layer.
The mesh reinforces the system by improving tensile strength and helping to reduce the risk of cracking over time. This is a vital part of the installation process, as it helps the system cope with movement and external stresses while maintaining a strong, consistent surface.
The mesh should be fully embedded into the upper third of the basecoat layer, ensuring it is covered properly and laid flat without creases or ridges.
Once embedded, this reinforced basecoat layer forms a strong and reliable foundation for the finishing coats.
5. Applying a Second Coat of EWI-748 Lime Basecoat
Once the mesh has been embedded, a second pass of EWI-748 Lime Basecoat may be used as needed to fully cover the mesh and achieve a smooth, even surface.
This helps ensure the reinforcement layer is properly encapsulated and that the wall is prepared for the final finish coat.
At this stage, the system begins to take on its full strength, combining the breathability of lime with the thermal and acoustic benefits of wood fibre insulation.
Allow the basecoat to dry properly before moving on to the finish layer.
6. Applying EWI-749 Fine Finish Lime Plaster
Once the reinforced basecoat has dried, EWI-749 Fine Finish Lime Plaster can be applied.
This finishing plaster provides the final textured or smooth decorative lime finish, depending on the chosen application method and desired appearance. It has been developed to complement breathable systems and works particularly well over lime basecoats and wood fibre insulation.
As a lime-based finish, it remains vapour permeable and helps preserve the breathable qualities of the full system. It also delivers a natural appearance that is especially suited to traditional, character and heritage-style properties.
The plaster should be applied evenly and finished to the required texture.
7. Applying EWI-705 Lime Paint
After the finish lime plaster has dried, the next step is to apply EWI-705 Lime Paint.
This breathable decorative coating enhances the appearance of the finished façade while maintaining the vapour permeability of the overall system. It provides a traditional mineral finish that works in harmony with the lime plaster beneath.
Lime paint is ideal for breathable wall systems because it allows moisture vapour to continue passing through the wall, rather than sealing the surface with a less permeable coating.
It also helps complete the final appearance of the project, making it suitable for both renovation work and attractive external finishes on new breathable wall systems.
8. Optional EWI-707 Lime Wash
For additional sealing and protection, EWI-707 Lime Wash can be applied as an optional final step.
This product can help seal the surface while still working sympathetically with the breathable nature of the lime system. It is particularly useful where a traditional finish is desired or where extra surface protection is beneficial.
Using EWI-707 Lime Wash as part of the final build-up can help enhance the appearance and longevity of the completed lime finish.
Â
9. Why Choose a Lime onto Wood Fibre System?
A lime onto wood fibre system is an excellent choice for projects where breathability, sustainability and compatibility with traditional buildings are important.
By combining Wood Fibre insulation, screw fixings, EWI-748 Lime Basecoat, Fibreglass Mesh, EWI-749 Fine Finish Lime Plaster, EWI-705 Lime Paint and optional EWI-707 Lime Wash, the system provides:
-
Excellent breathability
-
Strong thermal performance
-
Natural moisture management
-
Good acoustic insulation
-
A durable lime-based finish
-
A system well suited to older and traditional properties
This makes it a strong option for homeowners, renovators and contractors looking for a natural and breathable external wall insulation solution.
If you are looking to buy products for a Lime onto Wood Fibre system, they are available from EWI Store. If you have any further questions, please contact our Sales team on 0203 034 0022.
Â