EXOPERM MONO DURO A2 – Class A2 Breather Membrane

EXOPERM MONO DURO A2 is a non-combustible, diffusion permeable monolithic breather membrane designed to meet a high level of fire performance. It has a Reaction to Fire classification of A2-s1, d0.

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  • A2-s1,d0 Reaction to Fire classification
  • Compliant with UK Building Regulations Approved Document B
  • Advanced glass fibre fabric for enhanced structural stability
  • Ideal for high-rise and higher-risk buildings
  • Highly vapour open with an Sd value of 0.09 m
  • Class W2 resistance to water penetration
  • Airtight with an air permeability value of 0,006 m³/m², h, Pa
  • High Permanent UV resistance without cladding, and with 50% and 50mm joints
  • Weather tight
  • Independently tested to EN 13501-1 for compliance
  • Improves energy efficiency of the building


EXOPERM MONO DURO A2 is a non-combustible external breather membrane designed for use on the cold side of insulation on façade wall and roof applications.

Suitable for:

  • Facades with open or closed joints
  • Roof applications
  • High-rise, high-risk and public buildings (schools, offices, commercial centres, hospitals, etc.)
  • Commercial and residential developments
  • Timber & steel framed constructions
  • Offsite construction
  • New builds and retrofits

Monolithic Technology

EXOPERM MONO DURO A2 is a non combustible roof underlay and wind barrier with a monolithic functional layer.

The monolithic functional layer provides enhanced protection for the building envelope:

  • transports vapour to outside
  • is vapour open whilst having excellent waterproofing properties
  • creates a complete wind tight, waterproof membrane that actively expels out any water/humidity unlike most micro-porous membranes that rely on small pores (which have the tendency to block)

Technical Data

WEIGHT EN 13859-2 225 g/m² 
REACTION TO FIRE EN-13501-1 A2-s1,d0
SD-VALUE M EN-13859-2 0.09 M
TENSILE STRENGTH MD / CD EN 13859-2 290 N / 390 N ± 75
NAIL TEAR RESISTANCE MD / CD EN 13859-2 4200 N/3100 N/50mm

1.5m X 50m=75m2 (59-1/16” X 164’-1/2” = 807 SF)