The numbers don’t lie

Why it is invariably more expensive to excavate and replace, rather than reline.

Before relining technology, the only option to repair a damaged pipe was to excavate and replace the line. At best, excavation involved digging down through soft ground causing a little mess and a temporary (et bearable) disruption of your domestic harmony. At worst, you’re looking out the window, protecting your eyes and ears from the jackhammer that is demolishing your driveway, distraught at the thought of the bill you’re yet to receive and wondering when the nightmare might end. 

Relining technology was developed to avoid excavation, providing a less disruptive and cheaper alternative, which is exactly what it does. And whilst there are varying degrees of excavation, rarely (if ever) is it a cheaper option than relining, not to mention relining is much more pleasant. 

We have outlined three separate scenarios, taken from real-world projects, that compare an excavation and relining solution side by side so that you can see that the numbers don’t lie when you’re deciding whether to dig and replace or simply, reline. 

01 – Root infested sewer line

Tree roots have compromised the sewer line that runs from your property to the boundary tap. It is buried 2m under your pristine lawn and; there is no access for an excavator! CC.TV inspections have identified a significant blockage and multiple cracks in the old terracotta pipe that is 10m in length.


  • Clear the line using a high-pressure jetter, no excavation.
  • Reline the old pipe, creating a new, stronger more durable one within the damaged exterior
  • PRICE: $5000 +GST

Excavate & Replace

  • Manually dig a huge trench along the section of damaged pipe, completely ruining your prize winning lawn. 
  • Shoring of the trench, which is required when working in ground deeper than 1.5m.
  • Clear dirt from around the pipe and fully excavate the line, increasing the risk of ground shifting.
  • Cutaway tree roots and replace the terracotta pipe with a new PVC pipe.
  • Replace the soil & patch the lawn (with more soil, creating an ugly mess).
  • PRICE: $12,000 +GST

02 – A damaged drain that runs under the pool

To everyone’s delight, you have installed a pool in your backyard – just in time for summer. To your despair, the original sewer drainage runs under the new pool and has become damaged due to ground movement, causing cracks and misalignments in your summer which is 20m in length. 


  • Clear the line using a high-pressure jetter, no excavation.
  • Reline the old pipe, creating a new, stronger, more durable one within the damaged exterior.
  • Price: $10,000 +GST

Excavate & Replace

  • The pipe cannot be diverted due to height issues regarding the correct fall of the pipe to connect to the sewer main.
  • The pool or and surrounding area has to be excavated to gain sufficient access to the pipework to repair the damage or replace the line entirely.
  • Resulting in major groundworks and a significant tidy up including landscaping.
  • PRICE: Upwards of $40,000 +GST
Andre working beneath a family pool.

03 – Blockages beneath the bathroom

The waste line from the house to the boundary tap has become compromised due to ground movement, causing sewage to back up into the bathroom. The damaged pipe is located under the new, polished concrete floor of the bathroom and a stencil crete driveway. The pipe is 30m long including 3 junction connections.


  • Clear the line using a high-pressure jetter, no excavation.
  • Reline the old pipe, creating a new, stronger, more durable one within the damaged exterior.
  • Robotically reinstatement of three junctions.
  • PRICE: $16,500 +GST

Excavate & Replace

  • Excavate bathroom concrete floor to gain access to replace pipework.
  • Excavate a channel a trench down the stencil crete driveway.
  • Replace all pipework, backfill, reinstate concrete floor and foundations, reinstate stencil crete driveway with a strip of new concrete.
  • Price: Upwards of $35,000 +GST
Our mission was to keep this drivway intact – we succeeded.

You may have noticed that the relining process rarely deviates from 3 simple steps:

  1. Clear the line. 
  2. Install a new, stronger pipe in the carcass of the old one.
  3. Leave without causing a mess.

From time to time and typically due to a unique combination of circumstances, the old school dig and replace technique may still be employed, but for the vast majority of pipe, drain and sewer faults, the simple application fo relining techniques will be much more cost-effective for your wallet and much less offensive on your eyes, ears and blood pressure.

If you have any questions at any time, please get in touch.

We’re your relining guys

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