Glapor Recycled Foamed Glass Gravel (RFG) is a lightweight, insulating, capillary-breaking aggregate and a core component of the Roundtower Limecrete Flooring System. Made from 100% recycled glass, Glapor provides a highly durable, vapour-permeable and plastic-free solution for sustainable floor insulation beneath limecrete slabs.
🏗️ The Roundtower Limecrete Flooring System
The Roundtower Limecrete System is designed for solid-walled buildings—especially where breathability and moisture control are essential. Unlike modern DPM-based concrete floors that can trap moisture, the Roundtower Limecrete floor works in harmony with traditional building materials to manage moisture movement safely and prevent rising damp.
The full system consists of:
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Glapor Foam Glass Gravel Layer
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Acts as load-bearing hardcore, insulation, and capillary break
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Laid to a minimum depth of 150mm (can be increased for more insulation)
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Compacted in layers for stability
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Geotextile Membrane
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Laid beneath and over the Glapor Foam Glass Layer to provide a seperation layer.
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Roundtower Limecrete Slab
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Made using Roundtower NHL 5, aggregate and fibres.
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Laid directly over the geotextile to form a solid, breathable base slab.
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The system offers excellent thermal mass, moisture buffering, and long-term breathability, making it an ideal solution for heritage renovations, listed buildings, and eco-conscious new builds.
🔍 Why Choose Glapor Foam Glass?
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✔️ Non-Capillary Active – Prevents rising damp without needing a DPM
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✔️ Breathable – Works within vapour-permeable floor systems
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✔️ Excellent Insulation – Thermal conductivity of ~0.080 W/m·K
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✔️ Environmentally Friendly – Made from recycled glass in a carbon-neutral process
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✔️ Resistant to Pests – Inert and unaffected by rodents, insects, fungi, or bacteria
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✔️ Lifelong Performance – Will not degrade, settle, or lose thermal effectiveness over time
📦 Specifications
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Material: 100% Recycled Foamed Glass
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Size Range: Typically 13–63mm
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Thermal Conductivity: 0.080 W/m·K
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Loose Bulk Density: ~100–120 kg/m³
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Pack Size: Delivered loose or in 1.5mÂł jumbo bags
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Applications: Limecrete floors, timber frame construction, eco-renovations, and civil engineering
🌱 Designed for Conservation & Comfort
The Roundtower Limecrete system, with Glapor at its core, is a modern, breathable alternative to damp-proofed concrete slabs—ensuring your floor remains dry, warm, and breathable without compromising the health of the building fabric.Â
