At Roundtower Lime, we supply a carefully curated range of breathable, sustainable, and high-performance insulation boards specifically selected for use in heritage and solid wall buildings, as well as environmentally conscious new builds. Our board systems are designed to work in harmony with traditional masonry, allowing walls to manage moisture safely and effectively while dramatically improving thermal performance.
We offer the following insulation board types:
1. Wood Fibre Boards (e.g. Steico)
Manufactured from sustainable timber sources, wood fibre boards are highly breathable, thermally efficient, and suitable for both internal and external wall insulation. Their open-pored structure allows for vapour diffusion while also buffering moisture, making them ideal for solid masonry retrofits. They also offer excellent acoustic insulation and are available in various densities and renderable finishes.
2. Cork Boards
Made from 100% natural cork, these boards are chemically free, highly breathable, and provide both thermal and acoustic insulation. Cork is harvested from the bark of the cork oak without harming the tree, making this one of the most environmentally friendly insulation materials available. Cork boards are particularly suitable for internal wall insulation on solid masonry and can be finished with lime plasters for a complete breathable system.
3. Wood Wool Boards (CE Woodwool)
These boards combine magnesium cement with wood strands to create a robust, breathable board that offers outstanding insulation and acoustic performance. They are ideal as a plaster carrier board for internal and external applications and are especially compatible with lime and clay-based plasters. Their strength also makes them suitable for ceiling and soffit insulation where fixings may be required.
4. Calcium Silicate Boards (SkamoWall)
Engineered for moisture control and mould resistance, calcium silicate boards are made from mineral-based materials and offer capillary-active properties. They are excellent for cold, damp-prone areas, especially basement walls or rooms with poor ventilation. These boards help regulate humidity by absorbing and releasing moisture without degrading over time. A full primer and plaster system is available to complement the board.
Why Choose Roundtower Lime Insulation Boards?
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Designed for moisture-sensitive and heritage buildings
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Fully compatible with lime plasters and renders
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Promote healthy indoor air quality
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Manufactured from natural, sustainable materials
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Excellent thermal and acoustic performance
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Solutions available for walls, floors, ceilings, and roofs
Frequently Asked Questions (FAQ)
Q1: Can I use these boards on stone or brick walls ?
A: Yes. All boards we supply are vapour open and work perfectly on solid masonry walls They allow moisture to migrate and evaporate naturally through the system, which is critical for solid wall buildings.
Q2: Which board offers the best thermal performance?
A: Wood fibre boards and cork boards both offer excellent thermal performance, with λ-values as low as 0.036–0.040 W/mK.
Q3: What finish can be applied over these boards?
A: All our boards can be rendered or plastered using breathable lime-based systems. Some boards (e.g., wood fibre, cork and calcium silicate) have specific primer and plaster systems that must be followed.
Q4: Can insulation boards be used externally?
A: Yes. Wood fibre and wood wool boards can be used externally as part of a breathable render system. External boards should always be detailed with care to manage rainwater and avoid trapped moisture.
Q5: Are these boards suitable for listed or protected buildings?
A: Absolutely. Breathable board insulation is often recommended for listed buildings where maintaining moisture balance and reversibility is critical. Always consult your conservation officer.
Q6: Do you offer guidance on installation?
A: Yes, Roundtower offers full technical support, installation guidelines, and system build-ups for each board type. We’re happy to assist you or your contractor throughout the specification and build process.
