This table lists the thermal resistance ranges and the accepted design specification values or averages of insulation materials, including older and less common materials that you may find in a house.
Table 3-1 Insulation Values
| Material | Ranges RSI/25.4mm(R/in.) | Design spec or average RSI/25.4mm(R/in.) |
|---|---|---|
| Polyurethane closed-cell spray foam | 0.97 to 1.14 (R-5.5 to 6.5) | 1.06 (R-6) |
| Polyurethane board | 0.97 to 1.2 (R-5.5 to 6.8) | 1.06 (R-6) |
| Extruded polystyrene board (XPS) | 0.88 (R-5) | 0.88 (R-5) |
| Polyisocyanurate spray foam | 0.85 to 1.46 (R-4.8 to 8.3) | 0.88 (R-5) |
| High-density glass fibre board | 0.63 to 0.88 (R-3.6 to 5) | 0.7 (R-4) |
| Expanded polystyrene board - Type I (EPS) | 0.67 (R-3.8) | 0.67 (R-3.8) |
| Expanded polystyrene board - Type Il (EPS) | 0.7 to 0.77 (R-4 to 4.4) | 0.7 (R-4) |
| Glass fibre roof board | 0.67 (R-3.8) | 0.67 (R-3.8) |
| Cementitious foam | 0.69 (R-3.9) | 0.69 (R-3.9) |
| Cotton fibre batt | 0.67 (R-3.8) | 0.67 (R-3.8) |
| Cork | 0.65 to 0.67 (R-3.7 to 3.8) | 0.65 (R-3.7) |
| Polyurethane open-cell spray foam | 0.63 to 0.67 (R-3.6 to 3.8) | 0.63 (R-3.6) |
| Polyurethane open-cell foam, poured | 0.7 (R-4) | 0.7 (R-4) |
| Cellulose fibre, wet sprayed | 0.53 to 0.67 (R-3 to 3.8) | 0.63 (R-3.6) |
| Cellulose fibre, blown, settled thickness | 0.53 to 0.67 (R-3 to 3.8) | 0.63 (R-3.6) |
| Mineral fibre batt | 0.53 to 0.7 (R-3 to 4) | 0.6 (R-3.4) |
| Wood fibre | 0.58 (R-3.3) | 0.58 (R-3.3) |
| Mineral fibre, loose fill, poured | 0.44 to 0.65 (R-2.5 to 3.7) | 0.58 (R-3.3) |
| Glass fibre batt | 0.55 to 0.76 (R-3.1 to 4.3) | 0.56 (R-3.2) |
| Glass fibre, loose fill, poured | 0.39 to 0.65 (R-2.2 to 3.7) | 0.53 (R-3) |
| Mineral fibre, loose fill, blown | 0.51 to 0.56 (R-3 to 3.8) | 0.53 (R-3) |
| Glass fibre, loose fill, blown | 0.48 to 0.63 (R-2.7 to 3.6) | 0.51 (R-2.9) |
| Fibreboard (beaverboard) | 0.41 (R-2.3) | 0.41 (R-2.3) |
| Mineral aggregate board (Insulbrick) | 0.41 to 0.7 (R-2.3 to 4) | 0.46 (R-2.6) |
| Wood shavings | 0.18 to 0.53 (R-1 to 3) | 0.42 (R-2.4) |
| Vermiculite* | 0.37 to 0.41 (R-2.1 to 2.3) | 0.38 (R-2.2) |
| Compressed straw board | 0.35 (R-2.0) | 0.35 (R-2.0) |
| Eel grass (seaweed) batt | 0.53 (R-3) | 0.53 (R-3) |
| Cedar logs | 0.18 (R-1) | 0.18 (R-1) |
| Softwood logs (other than cedar) | 0.18 to 0.25 (R-1 to 1.4) | 0.22 (R-1.25) |
| Hardwood logs | 0.12 (R-0.7) | 0.22 (R-1.25) |
| Straw bale | 0.23 to 0.28 (R-1.3 to 1.6) | 0.26 (R-1.45) |
| Radiant foil insulation | See Radiant foils | |
* See the vermiculite health and safety warning in Health and safety considerations.