Plinth & Perimeter Boards – Soprema XPS WF
High‑performance extruded polystyrene (XPS) insulation boards for plinths, splash zones and below‑ground perimeter applications.
Plinth & Perimeter boards are engineered for areas exposed to moisture, frost and mechanical loading, providing a robust thermal layer around the building perimeter. Their closed‑cell structure delivers exceptionally low water absorption, high compressive strength and long‑term thermal stability — ideal for insulating foundations, basement walls, slab edges and exposed plinth zones.
The boards can be installed against waterproofed masonry, concrete or insulation systems, and are suitable for both new build and retrofit. Their precision‑cut edges ensure tight joints, while the durable surface resists impact and site handling.
• Closed‑cell XPS insulation for plinths, splash zones and below‑ground use
• Extremely low water absorption and high freeze–thaw resistance
• High compressive strength for ground contact and backfilled areas
• Dimensionally stable, rot‑proof and resistant to soil moisture
• Compatible with Soprema waterproofing and façade systems
Available sizes:
600mm x 1250mm – 40mm boards are supplied as individual sheets, mainly for perimeter insulation for Limecrete floors.
Installation is straightforward, with boards easily cut to size and applied to surfaces. They can be used in conjunction with other systems for enhanced insulation and are compatible with various finishes.
| Material | Extruded polystyrene (XPS), closed‑cell |
| Thermal conductivity (λD) [W/m·K] | 0.033–0.036 (depending on thickness) |
| Compressive strength @ 10% deformation [kPa] | 300 |
| Water absorption (long‑term, immersion) [%] | ≤ 0.7 |
| Water absorption (diffusion) [%] | ≤ 3 |
| Water vapour diffusion resistance (µ) | 80–200 |
| Reaction to fire (EN 13501‑1) | E |
| Dimensional stability [%] | ≤ 5 |
| Temperature resistance [°C] | –50 / +75 |
| Edge profile | Square edge |
| Application zone | Plinths, perimeter insulation, below‑ground walls, splash zones |
