A trenchless technique developed by Dyno-Rod will allow insitu repair of decayed pitch fibre pipes (PFPs).
Because the pipes are prone to collapse as they age repair has not previously been an option.
PFPs were superseded 30 years ago but many are still in service, representing a replacement bill running to millions of pounds.
Unlike clay pipes or plastic, PFPs age badly. Fats, oils and hot water take a toll. Typically, worn PFPs flatten or go egg-shaped, then collapse. They often bubble inside as layers peel away.
The new repair method allows an initial re-rounding of damaged or collapsed pipes to allow conventional relining repair with newer pipe.
System developer Ken Scott says: 'Basically, we winch a conical dolly and/or a rotary cutter through the pitch fibre pipes to restore them to their original shape and remove enough damaged material to reline them.
'Key challenges that we've met are getting an 8t-10t winch through someone's house or garden or into tight spots in commercial and industrial premises and accessing drainage systems at whatever depth they are laid. But a nice plus is that the same technology will also remove damaged liners.'
Dyno-Rod tested techniques in collaboration with the University of East London's department of pipe line technology and management.
According to Margaret Burke, claims adviser at Royal & Sun Alliance, the method is significantly cheaper than excavation. At one job in Cornwall, where the system was developed, Dyno-Rod refurbished a domestic drainage system in just five hours and saved around £2,500 on a job that would have taken three days using excavation.
INFOPLUS www. dyno-rod. com