C578 Type XIV
ASTM C578 Type XIV is a high-density moulded expanded polystyrene (EPS), a rigid closed-cell styrenic foam graded under the ASTM C578 rigid cellular polystyrene family.
Reference datasheet — C578 Type XIV 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.
C578 Type XIV grades and fills
C578 Type XIV is supplied in 2 conditions, soft to hard.
Compare all 2 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
EPS39 geofoam block | Pick for lightweight embankment, bridge-abutment backfill and pavement base where 1% and 5% strain limits govern design. | 0.1 | 0.4 | 2 | — |
Graphite-enhanced EPS (grey/silver bead) at Type XIV density | Pick when the same 276 kPa load capacity is needed with roughly 10–15% lower thermal conductivity. | 0.24 | 0.42 | 2.2 | — |
Supply forms, finishes and certifications
Ways C578 Type XIV is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
FACED | Laminated / faced Type XIV board | Coating |
STDDefault | Standard unfaced block-molded EPS, Type XIV | Standard supply |
What is C578 Type XIV?
ASTM C578 Type XIV is a high-density moulded expanded polystyrene (EPS), a rigid closed-cell styrenic foam graded under the ASTM C578 rigid cellular polystyrene family. At a nominal density of 0.04 g/cm³ (40 kg/m³) it provides high compressive resistance with a thermal conductivity of 0.033 W/m·K, and is supplied as steam-moulded geofoam blocks, cut and planed boards, general-purpose sheet and faced panels. Service temperature is capped at 75 °C, and the foam must be permanently shielded from UV, solvents and hydrocarbons. Type XV is the next step up in load capacity, while XPS Type IV absorbs less water in sustained below-grade wetting. C578 Type XIV has a density of 0.04 g/cm³ (0.0014 lb/in³), lighter than 91% of polymer grades. Its glass-transition temperature is 100°C (212 °F). C578 Type XIV has a tensile strength of 0.45 MPa (0.0653 ksi), weaker than 90% of polymer grades. The elastic modulus is 0.01 GPa (0.0017 Msi).
What is C578 Type XIV used for?
- Heavy geofoam fill
- Bridge approach fill
- Structural insulation
Advantages
- Lightweight — 0.04 g/cm³ (0.0014 lb/in³), better than 91% of polymer grades
- Easy to machine — 85/100, better than 88% of polymer grades
- Low embodied carbon — 3.3 kg CO₂/kg, better than 78% of polymer grades
Limitations
- Poor heat conductor — 0.03 W/m·K (0.0191 BTU/hr·ft·°F), worse than 95% of polymer grades
- Degrades in UV without stabilisers — 20/100, worse than 88% of polymer grades
- Low stiffness — 0.01 GPa (0.0017 Msi), worse than 79% of polymer grades
C578 Type XIV properties
Typical room-temperature values; bars are the position among polymer grades.
Physical4
C578 Type XIV has a density of 0.04 g/cm³ (0.0014 lb/in³), lighter than 91% of polymer grades. Its glass-transition temperature is 100°C (212 °F).
Mechanical7
C578 Type XIV has a tensile strength of 0.45 MPa (0.0653 ksi), weaker than 90% of polymer grades. The elastic modulus is 0.01 GPa (0.0017 Msi).
Thermal8
C578 Type XIV is rated for continuous service to 75°C (167 °F). It conducts heat at 0.03 W/m·K (0.0191 BTU/hr·ft·°F), worse than 95% of polymer grades. Thermal expansion is 65 µm/m·K (36.1 µin/in·°F).
Electrical4
C578 Type XIV has an electrical resistivity of 1×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 65% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of C578 Type XIV takes about 105 MJ of energy and emits 3.3 kg of CO₂ — more than 54% of polymer grades. Typical recycled content is 10%.
Manufacturability4
C578 Type XIV's machinability is excellent (85/100, better than 88% of polymer grades); weldability poor (25/100); formability fair (40/100).
Common Calculations4
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. C578 Type XIV is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C578 Type XIV
Is C578 Type XIV easy to machine?
Cut with hot wire, hot knife, band saw or CNC router; use vacuum extraction for beads and avoid melting smear by keeping wire temperature just above 200 °C.
Can C578 Type XIV be welded?
Not conventionally welded — join with hot-air/hot-plate fusion of block faces or, more usually, with water-based, cement-based or bitumen-emulsion adhesives and mechanical fasteners.
Can C578 Type XIV be formed, bent or molded?
Produced by pre-expanding EPS beads then steam block-moulding (approx. 0.6–1.0 bar steam) or shape-moulding; age blocks several days before cutting to stabilise dimensions.
C578 Type XIV 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 |
|---|---|---|
| pentane (residual blowing agent)largely vented during ageing | 0.1 – 1.5 | 0.5 |
| polymeric brominated flame retardantPolyFR; HBCD phased out | 0.3 – 1.2 | 0.7 |
| graphite1–4% only in the GPS/grey-bead variant | ≈ 0 | 0 |
| polystyrene (styrene monomer units)expandable polystyrene bead resin | ≥ 95 (balance) | — |
What surface finishes work on C578 Type XIV?
No paint with solvent carriers — finish with cement/polymer render, EIFS base coat, water-based coatings, foil or film lamination; always cover to protect from UV and hydrocarbons.
How much does C578 Type XIV cost?
C578 Type XIV is a standard-cost polymer ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C578 Type XIV — frequently asked
What is C578 Type XIV used for?
C578 Type XIV is typically used for heavy geofoam fill, bridge approach fill and structural insulation. In short: high-density structural EPS; load-bearing geofoam fill; machinability score 85.
What is the tensile strength of C578 Type XIV?
C578 Type XIV has a typical tensile strength of 0.45 MPa (0.0653 ksi) — weaker than 90% of polymer grades. Strength varies by condition: see the 2 listed tempers.
Is C578 Type XIV easy to machine?
Yes — machinability is rated excellent (85/100, better than 88% of polymer grades). Cut with hot wire, hot knife, band saw or CNC router; use vacuum extraction for beads and avoid melting smear by keeping wire temperature just above 200 °C.
Can C578 Type XIV be welded?
Not readily — weldability is rated poor (25/100). Not conventionally welded — join with hot-air/hot-plate fusion of block faces or, more usually, with water-based, cement-based or bitumen-emulsion adhesives and mechanical fasteners.
What surface finishes work on C578 Type XIV?
No paint with solvent carriers — finish with cement/polymer render, EIFS base coat, water-based coatings, foil or film lamination; always cover to protect from UV and hydrocarbons.
Can C578 Type XIV be formed, bent or molded?
Produced by pre-expanding EPS beads then steam block-moulding (approx. 0.6–1.0 bar steam) or shape-moulding; age blocks several days before cutting to stabilise dimensions.
What is the maximum service temperature of C578 Type XIV?
C578 Type XIV is rated for continuous use to about 75°C (167 °F), and briefly to 85°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does C578 Type XIV cost?
C578 Type XIV is a standard-cost polymer ($$), 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 — Standard Specification for Rigid, Cellular Polystyrene Thermal Insulation — ASTM International (2022)
- ASTM D6817 — Standard Specification for Rigid Cellular Polystyrene Geofoam — ASTM International (2021)
- EPS Industry Alliance technical bulletins (physical properties, geofoam design) — EPS Industry Alliance (2023)
- Neopor / graphite EPS insulation board data — BASF (2023)
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.