Insulation R-Values for building components

Calculating Assembly Wall R-Value* Formula: Assembly R-value = 1 / (Assembly U-value) = 1 / (U-studs x % + U-cavity x %) Component R-Value Studs R-Value Cavity Assembly R-Value Wall - Outside Air Film (winter) 0.17 0.17   Siding - Wood Bevel 0.80 0.80   Plywood Sheathing - 1/2" 0.63 0.63   3 1/2" Fiberglass Batt   13.00   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 7.11 15.73   Wall Component U-Values 0.1406 0.0636   Total Wall Assembly R-Value     13.31 * This example is just for wood frame construction. Steel studs are a more complicated calculation. R-Value Table - English (US) Units Material R/ Inch hr·ft2·°F/Btu R/ Thickness hr·ft2·°F/Btu Insulation Materials Fiberglass Batts 3.14-4.30      3 1/2" Fiberglass Batt   11.00    3 5/8" Fiberglass Batt   13.00    3 1/2" Fiberglass Batt (high density)   15.00    6 1/2" Fiberglass Batt   19.00    5 1/4" Fiberglass Batt (high density)   21.00    8" Fiberglass Batt   25.00    8" Fiberglass Batt (high density)   30.00    9 1/2" Fiberglass Batt   30.00    12" Fiberglass Batt   38.00 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) 3.60-3.701   Cellulose Blown (wall) 3.80-3.901   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) 5.0-5.6   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    2x4 (3 1/2")   4.38    2x6 (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 Summer Interior Wall   0.68 Exterior Wall   0.25 Interior Ceiling Horizontal   0.92 Interior Ceiling 45°   0.76 Exterior Ceiling   0.25 Winter Interior Wall   0.68 Exterior Wall   0.17 Interior Ceiling Horizontal   0.61 Interior Ceiling 45°   0.62 Exterior Ceiling   0.17 Air Spaces 1/2" to 4" approximately   1.00
		1 Measured Thermal Resistance of Cellulose Insulation Products Commercially Available in 2007

Source:http://www.coloradoenergy.org/procorner/stuff/r-values.htm