XPS
ASTM C578 · EN 13164 · GB GB/T 10801.2
XPS is extruded closed-cell polystyrene board covered by C578, EN 13164 and GB/T 10801.2, with compressive-strength classes from X150 to X500 plus B1/B2 flame-retardant and grooved-face options.
Reference datasheet — XPS is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the X250 condition
XPS grades and fills
XPS is supplied in 8 conditions, soft to hard. X250 is the default FabDigit quotes; the values on this page are for it.
Compare all 8 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
X150 / ASTM C578 Type X | Lightest economy grade for cavity walls, sheathing and non-load-bearing insulation. | 0.26 | 0.3 | 3 | |
X200 / W200 | Intermediate grade for wall and floor heating layers where 250 kPa is not required. | 0.35 | 0.4 | 3 | |
X250Default X250 / ASTM C578 Type IV | Mainstream building board for roofs, floors and under-slab insulation; best cost/strength balance. | 0.4 | 0.45 | 3 | |
flame-retardant board, GB 8624 B1(B) rating | Mandatory grade for most Chinese building façade and roof insulation projects requiring B1 fire performance. | 0.4 | 0.45 | 3 | |
flame-retardant board, GB 8624 B2 rating | Economy fire-rated board for floors, under-slab and non-façade uses where only B2 is required. | 0.4 | 0.45 | 3 | |
X300 / ASTM C578 Type VI | For loaded floors, inverted roofs and cold-store floors with moderate traffic. | 0.45 | 0.5 | 3.5 | |
X350 / ASTM C578 Type VII | High-strength grade for road/railway frost protection and heavy under-slab loads. | 0.52 | 0.6 | 3.5 | |
X500 / ASTM C578 Type V | Highest-density XPS for airport aprons, tank bases, deep foundations and other high compressive loads. | 0.7 | 0.8 | 4 |
Supply forms, finishes and certifications
Ways XPS is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
GROOVED | Skin-removed / grooved board for plastering systems | Surface finish |
What is XPS?
XPS is extruded closed-cell polystyrene board covered by C578, EN 13164 and GB/T 10801.2, with compressive-strength classes from X150 to X500 plus B1/B2 flame-retardant and grooved-face options. Continuous extrusion with gas injection gives a skinned, higher-density board — 0.032 g/cm³ default, 0.45 MPa tensile strength, 0.012 GPa modulus and 0.029 W/m·K conductivity — so it holds thermal performance in damp and load-bearing positions where EPS does not. Boards are rigid and are cut rather than formed, service is limited to 75 °C, and the surface degrades under UV or solvent contact, so render, screed or membrane cover is required. EPS is the cheaper option for dry above-grade work. XPS has a density of 0.03 g/cm³ (0.0012 lb/in³), lighter than 93% of polymer grades. Its glass-transition temperature is 100°C (212 °F). XPS has a yield strength of 0.4 MPa (0.058 ksi) and a tensile strength of 0.45 MPa (0.0653 ksi) — weaker than 96% of polymer grades. Elongation at break is 3% and the elastic modulus is 0.01 GPa (0.0017 Msi).
What is XPS used for?
- Roof/wall insulation panels
- Below-grade insulation
- Floral/craft foam
- Cold storage panels
Advantages
- Easy to machine — 90/100, better than 95% of polymer grades
- Lightweight — 0.03 g/cm³ (0.0012 lb/in³), better than 93% of polymer grades
Limitations
- Poor heat conductor — 0.03 W/m·K (0.0168 BTU/hr·ft·°F), worse than 98% of polymer grades
- Low strength — 0.4 MPa (0.058 ksi), worse than 96% of polymer grades
- Degrades in UV without stabilisers — 15/100, worse than 95% of polymer grades
- Limited ductility — 3%, worse than 83% of polymer grades
- Low stiffness — 0.01 GPa (0.0017 Msi), worse than 79% of polymer grades
XPS properties
Typical room-temperature values for XPS-X250; bars are the position among polymer grades.
Physical4
XPS has a density of 0.03 g/cm³ (0.0012 lb/in³), lighter than 93% of polymer grades. Its glass-transition temperature is 100°C (212 °F).
Mechanical10
XPS has a yield strength of 0.4 MPa (0.058 ksi) and a tensile strength of 0.45 MPa (0.0653 ksi) — weaker than 96% of polymer grades. Elongation at break is 3% and the elastic modulus is 0.01 GPa (0.0017 Msi).
Thermal9
XPS is rated for continuous service to 75°C (167 °F). It conducts heat at 0.03 W/m·K (0.0168 BTU/hr·ft·°F), worse than 98% of polymer grades. Thermal expansion is 70 µm/m·K (38.9 µin/in·°F).
Electrical3
XPS has an electrical resistivity of 1×10¹⁴ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (75/100), worse than 66% of polymer grades. UV resistance is poor.
Sustainability3
Producing a kilogram of XPS takes about 100 MJ of energy and emits 4.5 kg of CO₂ — less than 61% of polymer grades. Typical recycled content is 10%.
Manufacturability4
XPS's machinability is excellent (90/100, better than 95% of polymer grades); weldability poor (20/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the polymer family
Yield strength against density for every polymer grade FabDigit runs. XPS is highlighted; hover a dot for its name, or open the interactive family chart.
Working with XPS
Is XPS easy to machine?
Cuts easily with hot wire, knife, fine-tooth saw or CNC router; keep speeds low and vacuum the dust, and avoid overheating that melts/collapses cells.
Can XPS be welded?
Not structurally weldable; joints are made by tongue-and-groove interlock plus water-based or PU foam adhesive and taped seams.
Can XPS be formed, bent or molded?
Produced by continuous extrusion foaming with gas injection then sizing/skinning; boards are rigid and only mildly thermoformable, so shapes are cut rather than formed.
XPS chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| blowing agent (CO2 / HFO-1234ze / HCFC-1residual gas in closed cells; determines aged λ and carbon footprint | 1 – 6 | 3 |
| flame retardant (brominated polymeric FRwith Sb2O3 or phosphate synergist in B1 grades | 0.5 – 2.5 | 1.2 |
| talc (nucleating agent) | 0.2 – 1.5 | 0.5 |
| pigment / colourantblue/pink/green brand colours | 0.05 – 0.5 | 0.2 |
| polystyrene (styrene homopolymer)GPPS resin, often with some recycled PS | ≥ 90 (balance) |
What surface finishes work on XPS?
Solvent-free coatings only; needs skin removal or grooving for plaster/mortar adhesion, and must be covered (render, screed, membrane) because it degrades under UV.
Equivalent designations
Standards and trade names that resolve to XPS in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- C578
- EN / DIN / Werkstoff-Nr.
- 13164
- GB (China)
- GB/T 10801.2
How much does XPS cost?
XPS is a standard-cost polymer ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
XPS — frequently asked
What is XPS used for?
XPS is typically used for roof/wall insulation panels, below-grade insulation, floral/craft foam and cold storage panels. In short: stronger, drier than EPS; closed-cell moisture resistance; below-grade insulation standard.
What is the yield strength of XPS?
XPS has a typical yield strength of 0.4 MPa (0.058 ksi) and a tensile strength of 0.45 MPa (0.0653 ksi) — weaker than 96% of polymer grades. Strength varies by condition: see the 8 listed tempers.
Is XPS easy to machine?
Yes — machinability is rated excellent (90/100, better than 95% of polymer grades). Cuts easily with hot wire, knife, fine-tooth saw or CNC router; keep speeds low and vacuum the dust, and avoid overheating that melts/collapses cells.
Can XPS be welded?
Not readily — weldability is rated poor (20/100). Not structurally weldable; joints are made by tongue-and-groove interlock plus water-based or PU foam adhesive and taped seams.
What surface finishes work on XPS?
Solvent-free coatings only; needs skin removal or grooving for plaster/mortar adhesion, and must be covered (render, screed, membrane) because it degrades under UV.
Can XPS be formed, bent or molded?
Produced by continuous extrusion foaming with gas injection then sizing/skinning; boards are rigid and only mildly thermoformable, so shapes are cut rather than formed.
What is the maximum service temperature of XPS?
XPS is rated for continuous use to about 75°C (167 °F), and briefly to 85°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between XPS X250 and XPS X500?
X250 is the default condition — mainstream building board for roofs, floors and under-slab insulation; best cost/strength balance. X500: highest-density XPS for airport aprons, tank bases, deep foundations and other high compressive loads. Yield strength is 0.4 MPa in X250 versus 0.7 MPa in X500.
How much does XPS cost?
XPS is a standard-cost polymer ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM C578-22 Standard Specification for Rigid, Cellular Polystyrene Thermal Insulation — ASTM International (2022)
- EN 13164:2012+A1:2015 Thermal insulation products for buildings — Factory made XPS products — CEN (2015)
- STYROFOAM Brand XPS Insulation product data — Dow / DuPont Performance Building Solutions (2023)
- FOAMULAR XPS Insulation technical bulletins (Types X, IV, VI, VII, 600/1000) — Owens Corning (2022)
- Inventory of Carbon & Energy (ICE) — insulation materials — University of Bath / Circular Ecology (2019)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.