R-Value Table

Insulation Values For Selected Materials

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. See the following example:

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	0.17	0.17
Siding - Wood Bevel	0.80	0.80
Plywood Sheathing - 1/2"	0.63	0.63
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
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
Interior Ceiling		0.61
Interior Wall		0.68
Exterior		0.17
Air Spaces
1/2" to 4" approximately		1.00

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Last Updated: 07/29/2008

R-Value Table

Insulation Values For Selected Materials

Calculating Assembly Wall R-Value* Formula: Assembly R-value = 1 / (Assembly U-value) = 1 / (U-studs x % + U-cavity x %)

* This example is just for wood frame construction. Steel studs are a more complicated calculation.

R-Value Table

Calculating Assembly Wall R-Value*
Formula: Assembly R-value = 1 / (Assembly U-value) = 1 / (U-studs x % + U-cavity x %)