Compare the whole cost, not the quote
An excavation quote covers digging, replacing the pipe and backfilling. It frequently does not cover reinstating what was on top: the concrete driveway, the paving, the established garden, the retaining wall.
Once those are added, relining is usually the cheaper option as well as the less disruptive one. Ask for both quotes to include full reinstatement so you are comparing like with like.
What relining actually is
A resin impregnated liner is pulled into position inside the existing pipe through an access point, inflated so it presses against the old pipe wall, and cured in place. What sets is a structural pipe in its own right.
The relined section is jointless, which matters because joints are where roots get in. The bore is smooth, so it flows better than the original earthenware did. Design life is typically fifty years.
When digging is still the right answer
If a pipe has fully collapsed there is nothing left to line against. If the line is badly out of alignment, or the fall is wrong and water is sitting in a belly, relining preserves the fault rather than fixing it.
A camera survey tells you which situation you are in before you commit to either approach. Any plumber quoting a full excavation without having put a camera down the line first is guessing.
How long it takes
Most residential relining jobs are done within a day through existing access, with no excavation at all. Excavation on the same job is typically several days plus curing and reinstatement time.
For a family living in the house, that difference is often the deciding factor on its own.
Written by the team at Adlington Plumbing. Licensed plumbing and gas fitting across Newcastle, Lake Macquarie and the Central Coast. Licence 384065C.