Drain relining: no dig, no problem


Drain relining, a no-dig or ‘trenchless’ solution, is one of the most cost-effective and quickest ways to rectify cracked, leaking or damaged pipes or sewers, to strengthen the system and extend its working life considerably. The technique, which came of age in the mid ‘90s and has been improved steadily by UK drain companies ever since, can involve a wholesale replacement or a partial ‘patching’.

Drains without the digging

The benefits of a no-dig solution speak for themselves: a drain relining will not involve excavation, minimising traffic disruption and time spent on-site, as well as involving relatively little time with the damaged pipe out of operation. Removing excavation from the equation also minimises the risk of ‘collateral’ damage caused by digging and earth-movement, which can be the cause of substantial delays. The technique is also much quieter than a traditional excavation replacement, making it suitable for commercial and domestic spaces where machinery noise and dust would constitute an unacceptable disruption or inconvenience.

How it works

This pipe renovation technique is also a wholly practical solution, which can be applied to pipes with diameters as narrow as 100 millimetres and as wide as a metre and is malleable enough to handle an offset joint, a change of thickness or an acute-angled bend with ease. Applying the entire coating in one cohesive piece creates a smooth and sound covering without seams, which constitute points of weakness prone to leaking or splitting. The solution can be applied to almost any pipe material, whether ceramic, metal or polymer plastic, and can be applied to pipes of considerable length, up to hundreds of metres at a time. The benefits of the solution include a longer working life, minimal changes in diameter and superior flow rates as well as the prevention of tree-root intrusion into the ‘run’, or pipe system.

The details

In brief, the relining process consists of forming and inserting a malleable, adhesive liner inside a pipe, which adheres to the inside of the cracked or damaged pipe when an internal airbag is inflated to help the resin ‘skin’ find its place. The airbag is then removed and the resin hardened using a curing process, filling in cracks and fissures smoothly and creating a separate internal pipe. The process is normally preceded by a CCTV survey of the damaged pipework, and a thorough cleaning of the pipes using high-pressure water jets.

The system is recommended for damaged but whole pipes cracking or softening in place, which are still sufficiently intact to ‘guide’ the resin liner and air bag. It is often used in cases where diffuse cracking, splitting or softening is suspected, such as in the case of a slow leak in a water or waste pipe. The technique is suitable for small-scale domestic or commercial sites but also for specialist jobs where sensitivity and minimal disruption are required. To date, relining has been used in a range of major UK infrastructure projects, including hundreds of miles of water pipes, aging sewers from the Victorian era, canal- and river-side pipework, and even during the construction of Manchester’s tram service.

Author bio

The author is a property blogger knee-deep in renovation, who writes about DIY disaster and interior design. She visits the Jethrough website to find out about serious, structural plumbing and drain clearing.