Type of

Insulation

Material

Minimum

Density

Kg/cu. cm

Minimum

Thickness

mm

1

2

3

4

A

i)

Fibre glass or rockwool

10.4

12

ii)

Expanded polystyrene*

24

12

B

i)

Fibre glass or rockwool

10.4

25

ii)

Expanded polystyrene*

24

25

C

i)

Fibre glass or rockwool

12

50

ii)

Fibre glass or rockwool

24

25

iii)

Expanded polystyrene*

24

38

W

Approved weather proof

vapour barrier

*    Expanded polystyrene shall only be used in spaces where:

(1)  Requirement of Part 4 "Fire Safety" of the Building Code of Pakistan would otherwise not prohibit the use of polystyrene for other uses.

(2)  Temperature of the fluid in the duct or piping will not exceed 65 degree C.

(3)  Temperature of the duct metal will not exceed 65 degree C due to heat generating sources installed in ducting such as electric heaters.

(Table 13.4 of the Building Code of Pakistan)