Yes. An existing high-density polyethylene (HDPE) pipe can often be replaced using a pipe-bursting-style trenchless process. Because HDPE is ductile, it is usually cut or split lengthwise rather than fractured like a brittle clay, concrete or cast-iron pipe. Suitability must be confirmed through a specialist site assessment. The assessment should also determine when pipe replacement is better than repair for the actual service and fault.
Why HDPE is usually split
Conventional pipe bursting applies radial force to fracture a brittle host pipe. HDPE tends to stretch and deform instead, so a purpose-designed cutting or splitting head is generally used to slit the pipe wall.
The head is pulled through the existing pipe from an entry point to a reception point. An expander displaces the split pipe into the surrounding ground while pulling the replacement pipe behind it. This is commonly grouped under “pipe bursting”, although “pipe splitting” describes the process more accurately.
What determines feasibility?
The main considerations are:
- the host pipe’s material, outside diameter, wall thickness and pressure class
- whether it carries drinking water, drainage or another service
- the route, length, alignment, bends, joints, fittings and previous repairs
- collapses, obstructions or undocumented fittings that may stop the splitting head
- soil and groundwater conditions
- access for equipment and entry and reception points
- nearby structures and underground services
- the proposed replacement diameter and whether sufficient ground clearance exists for displacement or upsizing.
A deteriorated pipe may still be suitable because the host pipe is intentionally destroyed. However, a collapse, tight bend, hard obstruction or inadequate clearance can make splitting impractical. For a water service, the specialist should also assess whether a drinking-water pipe can be safely relined using an approved system instead.
Pipe splitting involves excavation, powerful pulling equipment and ground displacement near concealed services. Homeowners should not attempt it. Underground assets must be identified and physically located as required. Plans alone may not show their exact position or depth.
For a Sydney drain, contact our pipe relining team to compare lining with replacement after an on-site inspection. If pipe splitting is selected, use a specialist contractor with equipment and experience suited to the host pipe and site.