- 1. Installing Rockwool Dual Density Slabs
- 2. Preparing Adhesive for Mineral Wool
- 3. Applying the Adhesive to Mineral Wool Boards
- 4. Installing Mechanical Fixings
- 5. Applying the Basecoat and Embedding the Mesh
- 6. Applying Mineral Render
- 7. Applying Silicone Paint
- 8. Understanding the A1 Fire Rating
- 9. Why Choose the EWI Pro A1 Mineral Render System?
In today’s construction landscape, safety, sustainability and compliance are no longer optional, they’re essential. That’s why at EWI Store, we’re proud to offer the complete EWI Pro A1 Mineral Render System, combining exceptional fire safety, thermal performance and long-lasting durability.
Recently certified with an A1 fire rating from a UK-based testing lab, the highest level of fire resistance available, this mineral render system offers reassurance and protection across a wide range of projects, from large-scale residential developments to private refurbishments.
If you are looking for a render system that helps meet the latest fire safety requirements without compromising on performance or appearance, this could be the ideal solution.
The EWI Pro A1 Mineral Render System is a high-performance external wall insulation system made up of carefully selected non-combustible components that work together to create a façade that is safe, durable, breathable and regulation-compliant.
We have created this handy buyers guide to help you understand the key components of the system and how the full installation build-up works.
1. Installing Rockwool Dual Density Slabs
At the core of the EWI Pro A1 Mineral Render System is Rockwool External Wall Insulation Dual Density Slab, a premium mineral wool insulation board designed for use within non-combustible façade systems.
This insulation achieves Euroclass A1 fire classification, making it an ideal choice for projects where fire safety is a priority. Alongside its fire performance, Rockwool mineral wool also provides excellent thermal insulation, strong acoustic performance, vapour permeability and dimensional stability in changing weather conditions.
Mineral wool is especially well suited to projects that require a breathable system, helping reduce the risk of trapped moisture and condensation within the wall build-up.
Our Rockwool External Wall Dual Density Slabs are available in a range of thicknesses to suit different project requirements.
2. Preparing Adhesive for Mineral Wool
To secure the insulation boards in place, a high-performance adhesive is required. For this system, we recommend EWI-225 Premium Basecoat, which is specifically suited to mineral wool insulation.
EWI-225 is a versatile product that can be used both as an adhesive and as a reinforcing basecoat, helping to simplify the system build-up while maintaining excellent performance. It offers strong adhesion, vapour permeability, high elasticity and resistance to cracking, making it ideal for demanding external wall insulation applications.
Simply mix the dry bagged product with clean water using a paddle mixer until a consistent workable mix is achieved.
Premium Basecoat also provides:
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Dual-purpose use as adhesive and basecoat
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High strength
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Vapour permeability
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High elasticity
3. Applying the Adhesive to Mineral Wool Boards
When installing mineral wool insulation boards, the adhesive should be applied carefully to ensure a strong, even bond to the substrate.
Apply the adhesive around the perimeter of the board and place dabs through the centre. This method helps accommodate minor irregularities in the wall surface while ensuring reliable contact between the board and substrate.
Because mineral wool has a fibrous structure, it requires a suitable adhesive with excellent grab and bonding strength. EWI-225 Premium Basecoat has been developed to meet these requirements and is a dependable choice for this type of installation.
4. Installing Mechanical Fixings
In addition to adhesive, mineral wool boards should also be secured using mechanical fixings. This provides additional stability and helps ensure the insulation remains securely fixed over the long term.
Fixings are typically positioned with one fixing at each corner of the board and one through the centre, although the exact fixing pattern may vary depending on the project specification and substrate.
For mineral wool systems, we strongly recommend using appropriate fixings designed to suit the insulation thickness and substrate type. As a general rule, fixings should be long enough to allow secure anchorage into the wall beyond the insulation thickness.
Mechanical fixing is a key step in helping the full system perform safely and effectively.
5. Applying the Basecoat and Embedding the Mesh
Once the insulation boards are fixed in place, the next step is to create the reinforced basecoat layer.
This is done using EWI-225 Premium Basecoat together with White Fibreglass Mesh or Orange Fibreglass Mesh. The mesh is embedded into the wet basecoat layer to provide tensile strength and help prevent cracking, creating a reinforced and durable surface ready for the finishing coats.
This reinforcement layer is essential to the long-term performance of the system and plays a major role in maintaining a strong, consistent façade finish.
6. Applying Mineral Render
The next stage in the system build-up is the application of EWI-060 Mineral Render, which acts as the finishing render coat.
Mineral Render is a breathable, mineral-based finish developed specifically for use over mineral wool insulation systems. It offers Euroclass A1 fire performance, making it a vital component in the complete A1-rated system.
Alongside its fire classification, Mineral Render provides high vapour permeability, a natural textured appearance and reliable drying performance, even in cooler or damper conditions.
This makes it especially suitable for projects where fire safety and breathability are both key priorities, including residential blocks, schools, hospitals and other public buildings.
7. Applying Silicone Paint
To complete the system, EWI-005 Silicone Paint is applied as the final protective coating.
Although often seen as a decorative finish, silicone paint also plays an important protective role within the system. It is highly breathable, water-repellent and dirt-resistant, helping to protect the underlying mineral render from weathering and environmental degradation while maintaining the vapour permeability of the overall build-up.
EWI Pro Silicone Paint is available in a range of popular colours, allowing you to achieve the desired final appearance without compromising the A1 fire performance of the system.
8. Understanding the A1 Fire Rating
One of the most important features of this system is its A1 fire classification.
The EWI Pro A1 Mineral Render System has achieved full MW Fire Classification with Mineral Render and Silicone Paint, officially certifying the full system as A1 rated under the Euroclass system.
This is the highest possible level of fire performance and means the system is classed as non-combustible. For specifiers, contractors and property owners, this offers confidence that the system has been developed with safety and compliance in mind.
This classification is more than just a technical achievement. It reflects a commitment to creating safer buildings and supplying façade systems that meet the needs of modern construction.
9. Why Choose the EWI Pro A1 Mineral Render System?
The EWI Pro A1 Mineral Render System is a complete solution for projects where fire safety, breathability and durability all matter.
By combining Rockwool Dual Density Slabs, EWI-225 Premium Basecoat, Fibreglass Mesh, EWI-060 Mineral Render and EWI-005 Silicone Paint, the system provides:
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A1 fire-rated performance
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Excellent thermal insulation
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High vapour permeability
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Strong acoustic benefits
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A durable and attractive external finish
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Confidence in compliance for modern façades
Whether you are working on a large-scale residential development, a public building or a private refurbishment, this system offers a robust and dependable solution.
If you are looking to buy products from the EWI Pro A1 Mineral Render System, they are available from EWI Store. If you have any questions, please contact our Sales team on 0203 034 0022.
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