Tunnels / arches (refurbishment)
Old tunnels and arches can suffer from dampness and water ingress because of a failure of the original waterproofing system, or, in the case of the many Victorian railway arches found in the UK, because they were never designed to be occupied.
For practical reasons it is usually preferable to apply a new waterproofing system to the inside of the tunnel or arch. Even where it is technically possible to apply an externally applied waterproofing system, to do so would involve costly and disruptive excavation.
Safeguard offer a choice of two internally-applied waterproofing systems. Solutions are also available for the waterproofing of tunnels during construction.
Oldroyd Cavity Drainage Membranes
Oldroyd Xv Clear or Oldroyd Xp Plaster Membrane can be applied to the sides of the tunnel or arch using special sealed fixing plugs in much the same way as they are used to waterproof old basements. Both of these products work by redirecting the water ingress to a sump or suitable discharge point rather than physically holding it back. For this reason they are often used to waterproof Victorian tunnels and arches constructed from bricks which do not always have the strength to physically hold back water pressure.
Drybase Waterproofing Slurries
Drybase Tanking Slurry can be used in conjunction with Drybase Waterproof Plug and Drybase Universal Mortar to waterproof tunnels in refurbishment projects, as shown in the diagram below. Because this system physically holds back water pressure it is essential to ensure that the substrate is strong enough to take the pressure. Correct surface preparation is essential to ensure a good bond between the Drybase waterproofing coat and the substrate.
Drybase products are particularly well-suited to sewer-rehabilitation. Drybase Crystalline Active Tanking Slurry is specifically designed for use in the demanding environment found in sewers (low pH levels etc…)