What it involves

Pipe lining, is the rehabilitation or reinforcement of pipes without excavation. It has become the method of choice for rehabilitation of deteriorated underground sewers and pipes due to its low installation cost, ease and speed of installation and minimisation of ancillary requirements such as traffic re-routing and security. Cured in Place Pipe (CIPP) Lining is a method of repairing a pipe using a flexible tube impregnated with a resin, which forms a new pipe within the original host pipe once the resin cures.

At the heart of the CIPP system is the resin matrix. Until it is cured by Ultra Violet (UV) Light, it remains in a liquid state within the host material – a glass reinforced tube. UV cured CIPP liners are factory manufactured and have a long shelf life provided they are not exposed to UV light.

The Product

Factory engineered and protocol controlled installation

1. Outer foil – prevents damage and premature curing from sunlight

2. GRP layers factory impregnated with resin

3. High resin content inner layer for maximum mechanical and chemical resistance

4. Inner foil to encapsulate styrene during curing.

Removed after curing is complete.

Installation Process

1. Pull or winch liner into position depending on size

2. Inflate liner with air (using compressor/blower)

3. Pre-inspect inflated liner with light train CCTV camera for quality assurance.

4. Pass UV light train through inflated liner at a speed determined by the lining diameter & thickness, and intensity of the UV source (cure time circa 1m per minute)

5. Make good liner ends in man holes

6. Drill holes to re-establish all lateral connections


  • Access from both ends
  • 4 – 6 hours’ site access
  • Over-pumping/tankering for high flows
  • 150mm – 1800mm diameter
  • Less than 30 degree bends

When to use UV Cured CIPP and its benefits

The key features of UV Liners are a higher strength with a thinner liner thickness, curing without water and with the liner resin encapsulated between inner and outer foils. This translates to:

  • Very high strength with minimal diameter reduction within the host pipe, maintaining high flow capacity. The super smooth liner can in fact increase flow capacity, particularly in brick pipes.
  • Thinner, lighter and easier to handle liners

The installation technique, with the pre-inspection before curing and a computer controlled lamp; recorded curing process, ensures that quality control is similar to a factory engineered product. The resin encapsulation and lack of water involvement in the curing process practically eliminates the risk of environmental pollution.

The final differentiator from many alternative CIPP products is the installation speed. Manhole to manhole lengths are normally installed within four hour working windows.

Combined, these benefits make UV cured GRP liners particularly suited to applications including:

  • Culverts, sewers and drains under transport infrastructure – e.g. roads, railways, airport runways
  • Outfalls, particularly those discharging into sensitive water courses
  • Runs with connections into basements and residential homes (reducing the risk of styrene smells)
  • Sites with short working windows – e.g. transport infrastructure and buildings, factories, distribution centres, retail buildings
  • Large diameter pipe lining and reinforcement, due to the thinner profile and lower weight – e.g. main sewers, large culverts

Why choose McAllister Bros for UV Cured CIPP lining?

People – All senior members of staff including the Directors are manufacturer-trained and the company possesses over 10 years’ experience of successfully using the application. We enjoy close working relationships with our liner and plant suppliers which equates to unrivalled technical support for our customers
Materials – Our longstanding relationships forged over a decade with Europe’s leading manufacturers, coupled with high volume consumption, enables us to provide and install high quality liners at competitive prices
Plant – Since procuring our first rig in 2006, we have developed our fleet to provide a range of lorry-mounted and portable trolley-based curing units so that we can make use of the most appropriate equipment for each specific job. Site access can be an inhibiting factor, and we continue to modify and enhance our plant to overcome access issues e.g. we now have the longest light train cable in Europe enabling relatively remote curing. We also own the UK’s most powerful UV system with our Prokasro Professional UV Truck for curing large diameter pipes and culverts up to 2 metres. Use of the truck can half curing speeds.