Repair techniques - sewer & drains

Excavation or no-dig repair?

This key decision is invariably driven by two factors - cost and disruption.  Where excavation and complete replacement is highly disruptive or prohibitively expensive, for example under a motorway, railway line, hospital theatre or high rise stack, trenchless technologies will generally be used.

Where excavation is straightforward with easy access, or a no-dig repair is very complex, digging is generally the preferred option.

The easiest application of trenchless technology is where the host pipe, or the space where the new pipe will be formed, has the required gradient and is free or can be readily made free of obstructions.  The following techniques can then be considered (where a link is available we have more technical detail on the specific technique):

• Patch repair - short liner type
• Patch repair - mechanical type
• Lining (relining) - up to 225mm
• Lining (relining) - over 225mm
• Lining - over 1500mm
• Pipe bursting
• Pipe reaming
• Directional drilling
• Laser guided augering
• Slip lining.