As buried or immersed structures, tunnels are more at risk from water ingress than most other types of structures and repairing tunnels can be difficult, expensive and highly disruptive.

Therefore construction has to be right first time - and every time. Only technically proven systems should be utilised in the construction and maintenance of this key infrastructure assets. Waterproofing that is 100% effective is leaking. At best this can be unsightly in areas exposed to the public such as underground stations. At worst it will cause degradation of the structre itself, creating the potential of major remedial works and shorter service life for the tunnel.

The waterproofing system for a tunnel should be an integral part of the design from the outset. The tunnel designer must consider the acceptable level of water ingress - which should effectively be zero.

Traditional Techniques

Tunnel waterproofing has traditionally been based on sheet materials that are welded together on site to form a membrane. Waterproofing integrity is dependant on the continuity and quality of the numerous seams which are all potential weak points. This problem is exacerbated in tunnels of complex shape.

Watertight Solutions

Since the 1960's Pitchmastic PmB has been protecting the world's transportation assets using unique seamless waterproofing techniques.

Our products are suitable to be applied across a variety of substrates and in a wide range of climates.


  • Bored (NATM/SEM/SCL)
  • Cut & Cover Tunnels
  • Immersed Tunnels
  • Suspended Deck

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