SIP R-Values (Calculated R-Values)
| SIP Panel Thickness | |||||
| 4 1/2″ | 6 1/2″ | 8 1/4″ | 10 1/4″ | 12 1/4″ | |
| EPS | 14 | 21 | 28 | 35 | 42 |
| XPS | 20 | 30 | 38 | 48 | 58 |
| Polyurethane | * | * | * | N/A | N/A |
| *R-values vary between SIP manufacturers slightly
**Consult the panel manufacturer to obtain R-values |
|||||
- Calculated R-values for generic structural insulated panel (SIP), including 7/16” oriented strand board (OSB) on each side. The R-value of each OSB facing is R-0.55.
- Expanded polystyrene (EPS) is Type I per ASTM C578-11.
- Extruded polystyrene (XPS) is Type IV – Type X per ASTM C578-11.
- For polyurethane, polyisocyanurate, and extruded polystyrene, the tests must be done on samples that fully reflect the effect of aging on the product’s R-value. To age the sample, manufacturers must follow the procedure in paragraph 4.6.4 of GSA Specification HH–I–530A, or another reliable procedure.
- R-Values may vary by manufacturer and will vary by actual SIP thickness. Please consult SIP manufacturers for individual product R-value information and SIP thicknesses available.
- R-values do not include wall coverings (interior or exterior) and/or air film values.
- All listed R-values are at mean temperature of 75° F.
- For further explanation on SIP thermal performance and whole wall R-values, please see R-values in the Real World
