No Dig Technology – or more commonly known as ‘Drain Re-lining’, ‘Lining’, ‘In-situ Lining’ or ‘Drainage Rehabilitation’
No Dig Technology consists of re-using the remaining structure of an existing pipeline that in itself may be defective but can be rehabilitated without the need of a more costly or inconvenient excavation.
Many different installation methods can be used and many different materials are available but the outcome is always the same.
The most common type of drainage that ‘lining’ is used on is ‘clay pipework’. Clay pipework is particularly subject to displacements, cracks, root intrusion etc. However, lining can be used on virtually any pipeline as long as there is access to insert the liner. Lining can also be used around bends (subject to the type of liner selected) and at any length (subject to the installation process being used).
The Lining process consists of:
- Determining the extent of the defects in a given pipeline by a CCTV Survey.
- The pipeline is then cleaned thoroughly by HPW jetting
- The pipeline is then rechecked by CCTV.
- Materials are then selected and the material cut to size.
- Resin is then introduced to the ‘liner’ at which time the felt inside the ‘liner’ absorbs the resin. This is commonly called the ‘Wet out’ stage.
- The ‘liner’, now ‘wetted out’ is then pulled or pushed into the host pipe.
- Once in position the ‘liner’ is then inflated by a calibration hose and forced against the walls of the host pipe.
- After a period of time, and in consideration of ambient temperatures or the process being used, the ‘liner’ will ‘cure’ leaving a new pipe within the existing host pipe. This liner will create smooth bumps where displacements existed, seal cracks, make the run water tight and be impervious to root intrusion.
- The run of drainage is then ready for use and only millimetres smaller than it was before the ‘lining’ process was undertaken.
Inspect-A-Drain Ltd can undertake any lining works that are required in pipelines from 100mm to 300mm in diameter and only use the best available materials and up to date installation processes.
A recent job completed was at Trent College – Long Eaton where 90 metres off 225mm diameter clay drainage was rehabilitated in just a single morning – making it fit to use in the afternoon!