Based in Unit 102 Coolmine Ind Est

Wallmate CW Boards

Wallmate CW Boards contain a flame retardant additive to inhibit accidental ignition from a small fire source. The boards are, however, combustible and, if exposed to an intense fire, may burn rapidly. All fire classifications given in Dow literature on Wallmate CW insulation boards are based on small scale tests and may not reflect the reaction of the material under actual fire conditions.

Additional useful information on aspects of fire performance of extruded polystyrene in building applications is listed in BS 6203: 1989; Fire Characteristics and Fire Performance of Expanded Polystyrene Materials used in Building Applications.

wallmate cw boards

For more info regarding our energy saving solutions, 

get in contact with Usher Insulations today!

Four standard thicknesses of Wallmate CW insulation boards are available. Used in a typical cavity wall with outer leaf of brickwork and inner leaf of medium density blockwork ( 1500 kg/m3) the U-values in Table 1 below can be achieved.

Physical Characteristics of Wallmate CW

The properties and characteristics of Wallmate CW boards meet all the requirements of BS 3837 Part 2: 1990 Grade E 1.

Table 2 below gives typical values: more detailed test results are available from Dow on request.

Wallmate CW boards melt at 120°C: the maximum recommended continuous operating temperature is 75°C.

Table 1

Board thickness (mm)  U-Value (W/m2 K)
25 0.57
30 0.51
40 0.42
50 0.36
(Note: Maximum U-value for exposed walls = 0.45 W/m²K.)

Table 2

Properties  Standard  Unit Wallmate CW
Board size - mm 1200 x 450
Thicknesses  - mm 25, 30, 40, 50
Tolerances Length 
+ 6
+ 3
+ 2
Edge profile - - Shiplap
Thermal conductivity*
(at 10°C. 90 days)
BS 3837 Part 2: 1990
Appendix G
W/mK 0.025
Compressive strength^ BS 4370 Method 3 kN/m² 200
Water absorption BS 3837 Part 2: 1990
Appendix E
Water vapour permeability BS 3837 Part 2: 1990
Appendix D
ngm/Ns 1.6
Water vapour resistivity  BS 3837 Appendix C MNs/gm 625
Capillarity - -



*Measured at 10°C. 90 days, maximum value.
^At yield or 10% deflection (whichever comes first) minimum value.