Insulation Values For Selected Materials
Understanding how different building materials resist the flow of heat is fundamental to designing comfortable and energy-efficient spaces. The R-value quantifies this thermal resistance, with higher values indicating better insulation. The following table provides a comprehensive list of R-values for a wide array of insulation and construction materials, presented both per inch and for common thicknesses. To illustrate how these individual resistances contribute to the overall thermal performance of a building element, an example calculation demonstrates the process of determining the total R-value of a wall assembly by considering the thermal resistance of its various components, including framing members and insulation within the cavity. This approach allows for a detailed assessment of thermal performance and informed material selection in building design.
Use the R-value table below to help you determine the R-value of your wall or ceiling assemblies. To obtain a wall or ceiling assembly R-value you must add the r-values of the individual components together.
Calculating Assembly Wall R-Value
Formula: Assembly R-value = 1 / (Assembly U-value) = 1 / (U-studs x % + U-cavity x %)
| Example Component Assembly | R-Value Studs | R-Value Cavity | Assembly R-Value |
| Wall – Outside Air Film | 0.17 | 0.17 | |
| Siding – Wood Bevel | 0.80 | 0.80 | |
| Container Side Wall Steel Corrugation” | 0.33 | 0.33 | |
| 3 1/2″ Fiberglass Batt | 11.00 | ||
| 3 1/2″ Stud | 4.38 | ||
| 1/2″ Drywall | 0.45 | 0.45 | |
| Inside Air Film | 0.68 | 0.68 | |
| Percent for 16″ o.c. + Additional studs | 15% | 85% | |
| Total Wall Component R-Values | 7.12 | 13.73 | |
| Wall Component U-Values | 0.1404 | 0.0728 | |
| Total Wall Assembly R-Value | 12.05 |
* This example is just for wood frame construction. Steel studs are a more complicated calculation
R-Value Table
| Material | R/ Inch | R/ Thickness |
| Insulation Materials | ||
| Fiberglass Batt | 3.14-4.30 | |
| Fiberglass Blown (attic) | 2.20-4.30 | |
| Fiberglass Blown (wall) | 3.70-4.30 | |
| Rock Wool Batt | 3.14-4.00 | |
| Rock Wool Blown (attic) | 3.10-4.00 | |
| Rock Wool Blown (wall) | 3.10-4.00 | |
| Cellulose Blown (attic) | 3.13 | |
| Cellulose Blown (wall) | 3.70 | |
| Vermiculite | 2.13 | |
| Autoclaved Aerated Concrete | 1.05 | |
| Urea Terpolymer Foam | 4.48 | |
| Rigid Fiberglass (> 4lb/ft3) | 4.00 | |
| Expanded Polystyrene (beadboard) | 4.00 | |
| Extruded Polystyrene | 5.00 | |
| Polyurethane (foamed-in-place) | 6.25 | |
| Polyisocyanurate (foil-faced) | 7.20 | |
| Construction Materials | ||
| Concrete Block 4″ | 0.80 | |
| Concrete Block 8″ | 1.11 | |
| Concrete Block 12″ | 1.28 | |
| Brick 4″ common | 0.80 | |
| Brick 4″ face | 0.44 | |
| Poured Concrete | 0.08 | |
| Soft Wood Lumber | 1.25 | |
| 2″ nominal (1 1/2″) | 1.88 | |
| 2×4 (3 1/2″) | 4.38 | |
| 2×6 (5 1/2″) | 6.88 | |
| Cedar Logs and Lumber | 1.33 | |
| Sheathing Materials | ||
| Plywood | 1.25 | |
| 1/4″ | 0.31 | |
| 3/8″ | 0.47 | |
| 1/2″ | 0.63 | |
| 5/8″ | 0.77 | |
| 3/4″ | 0.94 | |
| Fiberboard | 2.64 | |
| 1/2″ | 1.32 | |
| 25/32″ | 2.06 | |
| Fiberglass (3/4″) | 3.00 | |
| (1″) | 4.00 | |
| (1 1/2″) | 6.00 | |
| Extruded Polystyrene (3/4″) | 3.75 | |
| (1″) | 5.00 | |
| (1 1/2″) | 7.50 | |
| Foil-faced Polyisocyanurate (3/4″) | 5.40 | |
| (1″) | 7.20 | |
| (1 1/2″) | 10.80 | |
| Siding Materials | ||
| Hardboard (1/2″) | 0.34 | |
| Plywood (5/8″) | 0.77 | |
| (3/4″) | 0.93 | |
| Wood Bevel Lapped | 0.80 | |
| Aluminum, Steel, Vinyl (hollow backed) | 0.61 | |
| (w/ 1/2″ Insulating board) | 1.80 | |
| Brick 4″ | 0.44 | |
| Interior Finish Materials | ||
| Gypsum Board (drywall 1/2″) | 0.45 | |
| (5/8″) | 0.56 | |
| Paneling (3/8″) | 0.47 | |
| Flooring Materials | ||
| Plywood | 1.25 | |
| (3/4″) | 0.93 | |
| Particle Board (underlayment) | 1.31 | |
| (5/8″) | 0.82 | |
| Hardwood Flooring | 0.91 | |
| (3/4″) | 0.68 | |
| Tile, Linoleum | 0.05 | |
| Carpet (fibrous pad) | 2.08 | |
| (rubber pad) | 1.23 | |
| Roofing Materials | ||
| Asphalt Shingles | 0.44 | |
| Wood Shingles | 0.97 | |
| Windows | ||
| Single Glass | 0.91 | |
| w/storm | 2.00 | |
| Double insulating glass (3/16″) air space | 1.61 | |
| (1/4″ air space) | 1.69 | |
| (1/2″ air space) | 2.04 | |
| (3/4″ air space) | 2.38 | |
| (1/2″ w/ Low-E 0.20) | 3.13 | |
| (w/ suspended film) | 2.77 | |
| (w/ 2 suspended films) | 3.85 | |
| (w/ suspended film and low-E) | 4.05 | |
| Triple insulating glass (1/4″ air spaces) | 2.56 | |
| (1/2″ air spaces) | 3.23 | |
| Addition for tight fitting drapes or shades, or closed blinds | 0.29 | |
| Doors | ||
| Wood Hollow Core Flush (1 3/4″) | 2.17 | |
| Solid Core Flush (1 3/4″) | 3.03 | |
| Solid Core Flush (2 1/4″) | 3.70 | |
| Panel Door w/ 7/16″ Panels (1 3/4″) | 1.85 | |
| Storm Door (wood 50% glass) | 1.25 | |
| (metal) | 1.00 | |
| Metal Insulating (2″ w/ urethane) | 15.00 | |
| Air Films | ||
| Interior Ceiling | 0.61 | |
| Interior Wall | 0.68 | |
| Exterior | 0.17 | |
| Air Spaces | ||
| 1/2″ to 4″ approximately | 1.00 | |