Extruded Polystyrene (XPS)
Romanian Technical Denomination: Polistiren Extrudat (XPS)
High-density rigid foam insulation with 100% closed-cell structure delivering exceptional compressive strength and near-zero water absorption.
LEVEL 1: QUICK UNDERSTANDING (EXECUTIVE SUMMARY)
INVESTORS & DEVELOPERSHigh-density rigid foam insulation with 100% closed-cell structure delivering exceptional compressive strength and near-zero water absorption.
Exterior foundation walls, basement perimeter insulation, and under-raft slab insulation, Inverted flat roofs (acoperiș terasă inversată) and green roof assemblies
01. TECHNICAL OVERVIEW & ENGINEERING CHARACTERISTICS
Extruded Polystyrene (XPS) compliant with SR EN 13164:2015. Continuous extrusion process creates a uniform closed-cell structure devoid of voids between beads. Delivers high compressive strength (300 to 700 kPa at 10% deformation) and extraordinary resistance to water absorption by total immersion (≤ 0.7% vol). Essential for below-grade foundation basements, inverted flat roofs, and perimeter plinth zones (soclu).
02. CONSTITUENTS & MANUFACTURING SPECIFICATION
- ▸Extruded melted polystyrene resin with blowing agents
- ▸Continuous extrusion and calibration into high-density closed-cell boards with smooth or waffle-embossed skins
✓ ADVANTAGES & STRENGTHS
- •Near-zero water absorption under direct contact with moist soil and ground water
- •Extreme compressive load resistance (up to 70 tons/m²)
- •Maintains thermal insulation R-value even in wet, high-humidity subterranean environments
- •Immune to freeze-thaw degradation cycles
⚠ LIMITATIONS & RISK FACTORS
- •Higher material cost compared to standard EPS
- •Combustible (Euroclass E); not permitted for full-height high-rise facade envelopes
- •Very low vapor permeability (μ = 80-250), acting as a vapor barrier that can trap moisture if misused on internal walls