Stramit is an internationally recognised brand. CSB has been used successfully for over 70 years in more than twenty countries. Stramit CSB combines a remarkable range of physical properties unmatched by any single alternative building board.

CSB has a very high strength to weight ratio, good thermal and acoustic insulation and outstanding resistance to fire. CSB can be produced with both square or tapered edges. Standard panels are produced with recycled paper surface. Specialist finishes available.

Stramit CSB is not brittle and does not crumble so that it can be sawn, glued, nailed, or drilled and finished with renders, plasters and paint.

Compressed Straw Board Technical data

Panel Sizes





Width of 40 and 60 mm boards

Nominal 800 ± 2 mm



38 mm = 19 kg /m2

Width 60 mm board only

Nominal 1200 ± 3mm



58 mm = 23 kg /m2


From 1200 to 3200



379 kg /m3


 Nominal 40 ± 2 mm





 Nominal 60 ± 2 mm



500 kg




Pull out Strength

49.44 kg

Thermal Conductivity

λ = 0.099 Wm-1K-1


Load Bearing

REI 45

Thermal Resistance

R = 0.5858 m2KW-1


Elastic Modulus Major Axis

163.2 MPa 


k = 0.081 W / mk 


Elastic Modulus Minor Axis

90.2 MPa 

Impact Resistance 

180 J without failure 


Bending Strength Major Axis

1.72 MPa 


210 J rupture 


Bending Strength Minor Axis

1.46 MPa 

Moisture Diffusion Resistance

RD = 4.6 * 109 ms-1


Tensile Strength Major Axis

6376 N 

Water vapour transmission 

65.5 MNs/gm 


Tensile Strength Minor Axis

2743 N 

Moisture Diffusion Resistance Coefficient

μ = 9.7


Load Bearing - 2.4 x 1.2 x 0.058 m panel

1800 kg evenly distributed

Spread of Flame

34 mm.min-1




Fire Resistance Class E 

30 mins [EI 30 (o i) D3] 


Sequestered Carbon per m2

- 63 kg CO2 per m2

Sound Absorption Co-efficient

NRC 0.13


Sequestered Carbon per m3

-1050 CO2 per m3

Acoustic - Single Partition 60 mm

33 dB




Acoustic - Double Partition 60 mm

45 dB


Water loading