Insulation Rigid Foam
DuPont STYROFOAM Brand Residential Sheathing
DuPont STYROFOAM Brand Residential Sheathing is a plastic-film-faced XPS rigid foam board for exterior wall sheathing, attic floors, crawl spaces, and below-grade walls. R-5.0 per inch, 15 psi compressive strength (ASTM C578 Type X). Thinner than Scoreboard — designed as a supplemental thermal break over studs rather than primary insulation. Plastic film facing improves nailability and provides a Class II vapor retarder. Requires a 15-min thermal barrier (minimum 1/2" gypsum) in occupied interior spaces.
Material
Extruded polystyrene (XPS)
Astm Type
C578 Type X
Color
Grey
Faced
Yes
Facing
Plastic film (both sides)
R Value Per Inch
5
Model Comparison
4 models
| Specification | 0.55" | 0.75" | 0.78" | 1" |
|---|---|---|---|---|
| Model | — | — | — | — |
| r_value | 2.75 | 4 | 3.9 | 5 |
| lowes_sku | 5014009669 | 3125297 | 5014009677 | 5014009671 |
Shared Specifications
All models| material | Extruded polystyrene (XPS) |
| astm_type | C578 Type X |
| color | Grey |
| faced | Yes |
| facing | Plastic film (both sides) |
| r_value_per_inch | 5 |
| board_size | 4 ft × 8 ft |
| coverage_sqft_per_board | 32 |
| compressive_strength_psi | 15 |
| water_absorption_pct_max | 0.1 |
| vapor_retarder_class | II (~1.0 perms) |
| thermal_barrier_required | Yes |
| Application | Exterior wall sheathing, attic floors, crawl spaces, below-grade walls |
| fire_rating | flame spread: ≤25 · smoke developed: ≤450 · standard: UL 723 / ASTM E84 |
| standards | ASTM C578 Type X, ASTM E84, ICC-ES ESR-4755 |
| ul_classification | D-369 |