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 |