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C578 Type X DRAIN

Finish state

DRAIN = grooved / channelled drainage board

Foundation-wall board with drainage grooves; choose for backfilled walls needing hydrostatic relief.

Standard cost $$

Values for the DRAIN condition

Other C578 Type X grades and fills

C578 Type X is listed in 4 conditions; see the grade overview at C578 Type X.

Compare all 4 grades and fillsHide
Grade · open for datasheetBest forYield MPaTensile MPaElong. %Hardness
DRAINThis page
Grooved / channelled drainage board
Foundation-wall board with drainage grooves; choose for backfilled walls needing hydrostatic relief.0.180.223—
Shiplap / tongue-and-groove edge board
Use where board-to-board joints must block air and thermal bridging without taping.0.250.33—
Low-GWP HFO / CO₂-blown formulation
Specify for green-building credits and codes phasing out HFC blowing agents; same Type X mechanicals, slightly different aged R.0.250.33—
GB 8624 B1 fire-rated board
Chinese building code grade with elevated FR loading for façade and roof insulation.0.320.42.5—

What is C578 Type X DRAIN?

C578 Type X DRAIN is C578 Type X supplied in the DRAIN condition — foundation-wall board with drainage grooves; choose for backfilled walls needing hydrostatic relief. C578 Type X DRAIN has a tensile strength of 0.22 MPa (0.0319 ksi), weaker than 96% of polymer grades. The elastic modulus is 0.01 GPa (7.25×10⁻⁴ Msi). C578 Type X DRAIN has a density of 0.02 g/cm³ (7.95×10⁻⁴ lb/in³), lighter than 97% of polymer grades. Its glass-transition temperature is 100°C (212 °F).

Advantages

  • Easy to machine — 92/100, better than 99% of polymer grades
  • Lightweight — 0.02 g/cm³ (7.95×10⁻⁴ lb/in³), better than 97% of polymer grades
  • Low moisture uptake — 0.1%, better than 77% of polymer grades

Limitations

  • Degrades in UV without stabilisers — 12/100, worse than 99% of polymer grades
  • Poor heat conductor — 0.03 W/m·K (0.0173 BTU/hr·ft·°F), worse than 96% of polymer grades
  • Low stiffness — 0.01 GPa (7.25×10⁻⁴ Msi), worse than 89% of polymer grades

C578 Type X DRAIN properties

Typical room-temperature values for C578 Type X DRAIN; 17 are specific to this condition. Other listed values are C578 Type X reference data and may not represent this condition. Bars are the position among polymer grades.

Physical4

C578 Type X DRAIN has a density of 0.02 g/cm³ (7.95×10⁻⁴ lb/in³), lighter than 97% of polymer grades. Its glass-transition temperature is 100°C (212 °F).

Density0.02 g/cm³7.95×10⁻⁴ lb/in³
Glass Transition (Tg)100°C212 °F
Water Absorption (24 h)0.1%
Water Absorption (Saturation)0.3%

Mechanical9

C578 Type X DRAIN has a tensile strength of 0.22 MPa (0.0319 ksi), weaker than 96% of polymer grades. The elastic modulus is 0.01 GPa (7.25×10⁻⁴ Msi).

Elastic (Young's) Modulus0.01 GPa7.25×10⁻⁴ Msi
Shear Modulus0 GPa5.8×10⁻⁴ Msi
Poisson's Ratio0.3
Tensile Strength (Ultimate)0.22 MPa0.03 ksi
Compressive Strength0.09 MPa0.01 ksi
Compressive Modulus0.01 GPa0 Msi
Flexural Strength0.16 MPa0.02 ksi
Flexural Modulus0 GPa6.53×10⁻⁴ Msi
Shear Strength0.1 MPa0.01 ksi

Thermal8

C578 Type X DRAIN is rated for continuous service to 74°C (165 °F). It conducts heat at 0.03 W/m·K (0.0173 BTU/hr·ft·°F), worse than 96% of polymer grades. Thermal expansion is 70 µm/m·K (38.9 µin/in·°F).

Thermal Conductivity0.03 W/m·K0.02 BTU/hr·ft·°F
Specific Heat Capacity1,400 J/kg·K0.33 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)70 µm/m·K38.9 µin/in·°F
Max Service Temperature (continuous)74°C165 °F
Min Service Temperature-60°C-76 °F
Flammability (UL 94)Combustible; contains flame retardant. Not normally UL 94 rated — building qualification is ASTM E84 (FSI ≤ 25, SDI ≤ 450) / NFPA 286 with a thermal barrier required in occupied spaces; China grade B1 (GB 8624).
Limiting Oxygen Index26%
Max Service Temperature (short-term)85°C185 °F

Electrical4

C578 Type X DRAIN has an electrical resistivity of 1×10¹⁴ Ω·m.

Electrical Resistivity1×10¹⁴ Ω·m3.94×10²¹ µΩ·in
Dielectric Constant (1 MHz)1.05
Dissipation Factor (1 MHz)3×10⁻⁴
Volume Resistivity1×10¹⁶ Ω·cm

Chemical & Environmental2

UV resistance is not recommended.

UV / Weathering ResistanceNot recommended12/100
Chemical Resistance SummaryGood against water, alkalis, dilute acids, salts and cement/lime slurries; attacked and dissolved by aromatic and chlorinated solvents, ketones, esters, gasoline/diesel, coal-tar and solvent-based adhesives — use only water-based or foam-compatible adhesives and membranes.

Sustainability3

Producing a kilogram of C578 Type X DRAIN takes about 105 MJ of energy and emits 5 kg of CO₂ — more than 54% of polymer grades. Typical recycled content is 10%.

Embodied Energy (primary production)105 MJ/kg45,142 BTU/lb
Embodied Carbon (primary production)5 kg CO₂/kg
Typical Recycled Content10%

Manufacturability3

C578 Type X DRAIN's machinability is excellent (92/100, better than 99% of polymer grades); formability poor (20/100).

MachinabilityExcellent92/100
Formability (cold)Poor20/100
Processing Melt Temperature (typ.)200°C392 °F

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with C578 Type X DRAIN

Is C578 Type X easy to machine?

Cut with hot wire, sharp knife or fine-tooth saw; routing and CNC hot-wire shaping are easy but generate static-clinging dust — vacuum extraction helps.

Can C578 Type X be welded?

Not weldable in the metal sense; boards are joined by shiplap laps, tape, foam-safe adhesive or mechanical washer fasteners, and can be hot-plate/heat fused only in specialist panel lines.

Can C578 Type X be formed, bent or molded?

Produced by tandem extrusion of PS melt with dissolved blowing agent through a slot die into a calibrator; downstream shaping is limited to cutting, grooving and skiving — no post-forming.

What surface finishes work on C578 Type X?

Never leave exposed to sunlight; overcoat with cementitious base coat/EIFS on planed board, or cover with cladding, and use only water-based or XPS-compatible (solvent-free) adhesives, membranes and mastics.

C578 Type X 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.

ElementSpec limit (wt %)Nominal
blowing agent (CO₂, HFO-1234ze, HFC-134aresidual cell gas + dissolved agent1.5 – 63.5
flame retardant (polymeric brominated st0.7 – 31.5
nucleating agent (talc)0.1 – 10.4
pigment / IR attenuator (carbon, graphit0 – 1.50.3
polystyrene (general-purpose PS, virgin matrix resin≥ 90 (balance)—

C578 Type X DRAIN — frequently asked

What is C578 Type X DRAIN used for?

C578 Type X DRAIN is typically used for heavy structural fill under slabs, high-load roof and deck insulation, protected membrane roofs with paver ballast, parking and plaza deck insulation, airport and highway pavement insulation and freezer and cold-storage floor insulation. In short: highest-load XPS grade; shiplap and HFO options; cut-only, no post-forming.

What is the tensile strength of C578 Type X DRAIN?

C578 Type X DRAIN has a typical tensile strength of 0.22 MPa (0.0319 ksi) — weaker than 96% of polymer grades. Strength varies by condition: see the 4 listed tempers.

Is C578 Type X DRAIN easy to machine?

Yes — machinability is rated excellent (92/100, better than 99% of polymer grades). Cut with hot wire, sharp knife or fine-tooth saw; routing and CNC hot-wire shaping are easy but generate static-clinging dust — vacuum extraction helps.

Can C578 Type X DRAIN be welded?

Not weldable in the metal sense; boards are joined by shiplap laps, tape, foam-safe adhesive or mechanical washer fasteners, and can be hot-plate/heat fused only in specialist panel lines.

What surface finishes work on C578 Type X DRAIN?

Never leave exposed to sunlight; overcoat with cementitious base coat/EIFS on planed board, or cover with cladding, and use only water-based or XPS-compatible (solvent-free) adhesives, membranes and mastics.

Can C578 Type X DRAIN be formed, bent or molded?

Produced by tandem extrusion of PS melt with dissolved blowing agent through a slot die into a calibrator; downstream shaping is limited to cutting, grooving and skiving — no post-forming.

What is the maximum service temperature of C578 Type X DRAIN?

C578 Type X DRAIN is rated for continuous use to about 74°C (165 °F), and briefly to 85°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

Sources

  1. ASTM C578 — Standard Specification for Rigid, Cellular Polystyrene Thermal Insulation — ASTM International (2022)
  2. GB/T 10801.2 — Extruded polystyrene board (XPS) for thermal insulation — SAC (2018)
  3. Extruded polystyrene insulation board technical data (FOAMULAR / STYROFOAM class products) — Owens Corning / DuPont Performance Building Solutions (2023)
  4. Handbook of Polymeric Foams and Foam Technology — Hanser (2004)
  5. Rigid polystyrene foam property and LCA records — Granta / ICE inventory (2022)

Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.