Thermal conductivity of building materials

Abstracted from ASHRAE (1989), with permission

Building Board

Description

Density
lb/ft3

Conductivity
Btu·inch/(hr·ft2·°F)

Gypsum or plasterboard, 0.5 in

50

1.11

Plywood (Douglas fir)

34

0.80

Hardboard, Medium-density

50

0.73

Hardboard, High-density, service temp. service underlay

55

0.82

Hardboard, High-density. standard tempered

63

1.00

Particleboard, Low-density

37

0.54

Particleboard, Medium-density

50

0.94

Particleboard, High-density

62.5

1.18

Insulation

Description

Density
lb/ft3

Conductivity
Btu·inch/(hr·ft2·°F)

Cellular glass

8.5

0.35

Glass fiber, organic bonded

4 to 9

0.25

Expanded perlite, organic bonded

1.0

0.36

Expanded rubber (rigid)

4.5

0.22

Expanded polystyrene extruded, Cut cell surface

1.8

0.25

Expanded polystyrene extruded, Smooth skin surface

1.8 to 3.5

0.20

Expanded polystyrene, molded beads

1.0

0.20

1.25

0.25

1.5

0.24

1.75

0.24

2.0

0.23

Cellular polyurethane (R11 exp.)(unfaced)

1.5

0.16

Polyisocynaurate (R11 exp.)

2

0.14

Mineral fiber with resin binder

15

0.29

Mineral fiberboard, wet-felted, Core or roof insulation

16 to 17

0.34

Mineral fiberboard, wet-felted, Acoustical tile

18

0.35

Loose Fill

Description

Density
lb/ft3

Conductivity
Btu·inch/(hr·ft2·°F)

Cellulosic insulation (milled paper or wood pulp)

2.3 to 3.2

0.27 to 0.32

Sawdust or shavings

8 to 15

0.45

Wood fiber, softwoods

2 to 3.5

0.30

Perlite, expanded

5 to 8

0.37

Vermiculite, exfoliated

7 to 8.2

0.47

Masonry materials / Concrete

Description

Density
lb/ft3

Conductivity
Btu·inch/(hr·ft2·°F)

Cement motor

116

5.0

Lightweight aggregates including expanded shale, clay or slate; expanded slags; cinders; pumice; vermiculite; also cellular concretes

120

5.2

100

3.6

80

2.5

60

1.7

40

1.15

Perlite, expanded

40

0.93

Sand and gravel or stone aggregate (oven-dried)

140

9.0

Sand and gravel or stone aggregate (not dried)

140

12.0

Stucco

116

5.0

Masonry units

Description

Density
lb/ft3

Conductivity
Btu·inch/(hr·ft2·°F)

Brick, common

120

5.0

Brick, face

130

9.0

Siding material (on flat surface)

Description

Density
lb/ft3

Conductivity
Btu·inch/(hr·ft2·°F)

Hardboard siding, 7/16 in

40

0.653

Woods

Description

Density
lb/ft3

Conductivity
Btu·inch/(hr·ft2·°F)

Maple, oak, and similar hardwoods

45

1.10

Fir, pine, etc.

32

0.80