The table below gives R values of various building materials. To obtain a wall or ceiling assembly R-value you must add the r-values of the individual components together (this won’t give you an entirely accurate R value if you’ve got thermal bridging but it is good enough for rough estimates).
If we are building a passive house brownstone we wouldn’t go by this table since we need more accurate values. But if we are doing a partial renovation where we might not be replacing a wall or blowing in insulation into an existing wall or two then this table is very useful to show us what to aim for.
And as you know every green contractor is obsessed with R value.
Wall Assembly R-Value Example:
| Component |
R-value |
| Wall – Outside Air Film |
0.17 |
| Siding – Wood Bevel |
0.80 |
| Plywood Sheathing – 1/2″ |
0.63 |
| 3 1/2″ Fiberglass Batt |
11.00 |
| 1/2″ Drywall |
0.45 |
| Inside Air Film |
0.68 |
| Total Wall Assembly R-Value |
13.73 |
R-Value Table
| Material |
R/ |
R/ |
| Insulation Materials | ||
| Fiberglass Batt |
3.14 |
|
| Fiberglass Blown (attic) |
2.20 |
|
| Fiberglass Blown (wall) |
3.20 |
|
| Rock Wool Batt |
3.14 |
|
| Rock Wool Blown (attic) |
3.10 |
|
| Rock Wool Blown (wall) |
3.03 |
|
| Cellulose Blown (attic) |
3.13 |
|
| Cellulose Blown (wall) |
3.70 |
|
| Vermiculite |
2.13 |
|
| Air-entrained Concrete |
3.90 |
|
| 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 |