Roundtower SuperTherm Wall Insulation is a breathable internal wall insulation system designed for solid masonry walls, period homes, and heritage properties. The system combines Roundtower SuperTherm insulating lime plaster with a Heritage Finish (CLM35) and embedded mesh reinforcement, delivering a durable, high-performance solution that improves energy efficiency while protecting building fabric.
Engineered for retrofit and conservation projects, SuperTherm is a lightweight, non-organic plaster with exceptional insulation properties (thermal conductivity λ = 0.0395 W/mK). Its vapour-permeable structure allows walls to breathe, significantly reducing the risk of interstitial condensation, mould, and trapped moisture — problems commonly found with synthetic insulation boards or foil-backed systems.
This internal insulation system is ideal for:
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Stone and brick walls in heritage buildings
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Cottages, townhouses, and solid wall terraces
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Listed or protected structures requiring breathable materials
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Damp or moisture-prone interiors needing thermal upgrades
Key Features:
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Outstanding thermal insulation with slim build-up
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Moisture-buffering to stabilise internal humidity levels
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Fully breathable and vapour-open – supports healthy walls
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Non-organic, rot-resistant, and compatible with lime-based systems
This system helps achieve modern comfort standards without compromising the breathability and integrity of traditional buildings. It’s ideal for architects, conservation officers, and homeowners seeking a natural, breathable insulation system that supports energy upgrades and heritage protection.
Frequently Asked Questions (FAQs)
Q: What is Roundtower SuperTherm made from?
A: SuperTherm is a lime-based insulating plaster made with hydrated lime, natural pozzolan (metakaolin), and an ultra-lightweight manufactured aggregate. It contains no cement, synthetic additives, or organic materials.
Q: Can SuperTherm be used on listed or historic buildings?
A: Yes. SuperTherm is vapour-permeable, non-invasive, and designed specifically for solid wall heritage buildings where breathability is essential. It is already in use on prominent public and protected structures across Ireland.
Q: How thick should the SuperTherm layer be?
A: Typical applications range from 30mm to 100mm depending on insulation requirements. A final 5mm mesh-reinforced Heritage Lime Finish is applied on top for a smooth, durable finish.
Q: Is SuperTherm suitable for damp walls?
A: Yes. Its high water storage capacity and breathability help manage internal moisture, buffer humidity, and reduce condensation risk — especially in older or poorly ventilated buildings.
Q: How does SuperTherm compare to synthetic insulation boards?
A: Unlike rigid synthetic boards, SuperTherm is fully breathable, compatible with lime substrates, and provides insulation while supporting moisture movement. It also avoids issues like cold bridging, trapped moisture, and VOC emissions.
