Unit Thermal Resistance Building Materials

Related Resources: heat transfer

Heat Transfer Engineering
Thermodynamics
Engineering Physics

Unit thermal resistance (the R-value) of common components used in buildings

Component	m² · °C / W	ft² · h · °F / Btu
Outside surface (winter)	0.030	0.17
Outside surface (summer)	0.044	0.25
Inside surface, still air	0.12	0.68
Plane air space, vertical, ordinary surfaces (eff= 0.82):
13 mm (1/2 in.)	0.16	0.90
20 mm (3/4 in.)	0.17	0.94
40 mm (1.5 in.)	0.16	0.90
90 mm (3.5 in.)	0.16	0.91
Insulation, 25 mm (1 in.)
Glass fiber	0.70	4.00
Mineral fiber batt	0.66	3.73
Urethane rigid foam	0.98	5.56
Stucco, 25 mm (1 in.)	0.037	0.21
Face brick, 100 mm (4 in.)	0.075	0.43
Common brick, 100 mm (4 in.)	0.12	0.79
Steel siding	0.00	0.00
Slag, 13 mm (1/2 in.)	0.067	0.38
Wood, 25 mm (1 in.)	0.22	1.25
Wood stud, nominal 2 in. x 4 in. (3.5 in. or 90 mm wide)	0.63	3.58
Wood stud, nominal 2 in. x 6 in. (5.5 in. or 140 mm wide)	0.98	5.56
Clay tile, 100 mm (4 in.)	0.18	1.01
Acoustic tile	0.32	1.79
Asphalt shingle roofing	0.077	0.44
Building paper	0.011	0.06
Concrete block, 100 mm (4 in.):
Lightweight	0.27	1.51
Heavyweight	0.13	0.71
Plaster or gypsum board,
13 mm (1/2 in.)	0.079	0.45
Wood fiberboard, 13 mm (1/2 in.)	0.23	1.31
Plywood, 13 mm (1/2 in.)	0.11	0.62
Concrete, 200 mm (8 in.):
Lightweight	1.17	6.67
Heavyweight	0.12	0.67
Cement mortar, 13 mm (1/2 in.)	0.018	0.10
Wood bevel lapped siding, 13 mm x 200 mm (1/2 in. x 8 in.)	0.14	0.81