Hot or Heat-cured lining is installed by inverting the liner with water. By turning it inside out it leaves the resin on the outside and smooth coating on the inside. The resin side will bond to the old sewer pipe giving it structural integrity and an increased lifespan of around 50 years.
Water is heated to around 80°C and is then circulated through the liner via a hose until the liner is cured which takes around 3-4 hours. Hot curing is incredibly popular in the industry but does have its drawbacks as it requires a tanker to act as a water source and a boiler unit on a separate truck. On the flip side, it’s relatively low-price after the initial cost of the water.
Steam cure lining adopts the same principle as Hot Cure Lining but as its name suggests uses steam and not water to help bond the new lining to the pipe or sewer. Steam Lining is quicker than Hot Cure with temperatures held at around 110°C to 120°C for around an hour. One of the big advantages of steam over water is that the installation and curing unit is one vehicle ensuring a much smaller footprint in the environment, especially in space-restricted or limited access areas.
There is however the added potential of ‘cold spots’ when steam curing if there is pooled water within the pipe or laterals, and on-site health and safety guidelines must be stringent due to the large quantity of hot steam being emitted from the boiler. A larger compressor than that needed for hot cure is also required.
