
When clearing is not the answer
If the pipe itself has failed, no amount of clearing fixes it. Here is how repair and relining actually work, and how to tell which one you need.
Drain repair restores a failed section of pipe, either by excavating and replacing it or by relining it in place. Relining — cured-in-place pipe lining — inserts a resin-saturated liner into the existing drain and cures it to form a new pipe inside the old one, sealing cracks, open joints and root entry points without digging up the full run. Relining suits pipe that is cracked or leaking but still structurally continuous; collapsed, crushed or severely deformed sections generally require excavation. A CCTV survey is what determines which applies.
Three findings mean the pipe, not the contents, is the problem:
You do not have to take anyone's word for any of this, and you should not have to. Ask to see it on camera.
The existing pipe is cleaned — usually by jetting, because resin will not bond to a dirty wall. A flexible liner saturated with resin is then inserted along the section and inflated against the inside of the old pipe, where it cures into a hard, jointless sleeve. The result is a new pipe formed inside the old one, with the joints and cracks sealed behind it.
The practical appeal is obvious: the driveway, the mature garden, the concrete patio and the established lawn stay where they are. The trade-off is that the new bore is very slightly smaller than the old one — almost never significant on a domestic lateral — and that the old pipe has to be in good enough shape to line against.
Relining is not a universal solution and it is worth being wary of anyone who presents it as one. A pipe that has fully collapsed has no shape to line against. A badly crushed or severely deformed section cannot take a liner properly. A drain with a significant back-fall — where a section has dropped so far that water sits in it — will still hold water after lining, because lining follows the existing alignment rather than correcting it. In those cases the section has to be dug up and replaced, and a quote that promises otherwise is one to question.
When it applies
There is no single right answer. What follows is what each approach is actually for.
A liner along the whole lateral. Suits a drain with defects at multiple points along a structurally continuous pipe — the classic older-Auckland earthenware line with roots at several joints.
A localised liner over a single defect. Considerably cheaper where the rest of the line is genuinely sound, which the camera has to demonstrate.
Dig down, cut out the failed section, replace with new pipe. Necessary for collapses, crush damage and back-falls that need re-grading. Sometimes simply the cheaper option where the fault is shallow and accessible.
Failures at connection points and around gully traps are common and often straightforward, since these are usually shallow and reachable.
Where a section has sagged and holds water, the fix is to excavate and relay it to correct fall. Lining will not solve this — it follows the existing shape.
Where a lateral has failed comprehensively along its length, replacement can cost less than repeatedly patching it. This is the least common outcome and should be evidenced, not asserted.
How it runs
A CCTV survey establishes what has failed, where, how far along, at what depth, and what condition the rest of the line is in. Nobody can honestly quote an underground repair without this.
The footage, the location, and a straight explanation of which approaches are genuinely available — including doing nothing for now, where that is reasonable.
A fixed written quote for a defined scope, valid 30 days. If access, consents or traffic management are needed, that is in the quote rather than a surprise later.
Relining or excavation as agreed, carried out or supervised under a PGDB licence, then a post-work camera pass so you can see the completed repair rather than take it on faith.
Cost
| What drives the price | Why it matters |
|---|---|
| Length of the failed section | Patching one metre and lining twenty are very different jobs. The camera survey is what establishes which you have. |
| Depth | Depth drives excavation cost more than almost anything else. A shallow repair near the gully is straightforward; three metres down is a different exercise entirely. |
| What is on top | Repairing under a lawn is one thing. Under a concrete driveway, a deck, established trees or a building is another, and reinstatement is a real cost that belongs in the quote. |
| Pipe diameter and material | Larger diameters cost more to line. Asbestos-cement pipe requires specific handling procedures that add time and cost. |
| Access for machinery | Whether a digger can reach the site, or whether it has to be dug by hand, changes the number substantially. |
| Consents and approvals | Work affecting the public network, or building over a public line, may require engineering approval from Auckland Council. |
Insist on: the CCTV evidence it is based on; the location and depth of the fault; exactly which method is proposed and why; what reinstatement is included — is the driveway being made good, and to what standard; the workmanship warranty and its length; and who is certifying the work. A repair quote with none of that behind it is a number, not a quote. You are entitled to ask, and to check the licence of whoever is signing it off.
For realistic dollar ranges across every drainage service, see our Auckland blocked drain cost guide. We give you a price before work starts, never after.
A large amount of Auckland's residential drainage is at or past the end of its design life, and the pattern of failure follows the pipe material.
Glazed earthenware in the pre-1960s suburbs — Ponsonby, Mt Eden, Epsom, Remuera — typically fails at the joints rather than through the barrel. The pipe itself is often in remarkably good order a century on; the mortar seals are not. That is the best possible relining scenario, because there is sound pipe to line against and the liner seals every joint in the relined run at once.
Asbestos-cement pipe, common in 1960s–80s housing, is safe undisturbed but requires specific handling once work starts. It should be identified before excavation begins, not during, and that is another argument for surveying first.
Concrete laterals suffer joint displacement through ground movement and, in some conditions, degradation of the invert. Early uPVC can suffer deformation where it was poorly bedded during installation.
Auckland's clay soils are the common thread. Seasonal shrink and swell moves jointed pipe over decades, and the failures that follow — open joints, steps, sags — are the ones we see most in West Auckland and across the North Shore.
All drainage repair must comply with the New Zealand Building Code — Clause G13 for foul water and Clause E1 for surface water — and repairing or altering a drain is restricted work under the Plumbers, Gasfitters, and Drainlayers Act 2006. It must be carried out or supervised by someone licensed by the PGDB. If the failure turns out to be on the public wastewater main rather than your lateral, it is Watercare's to repair at no cost to you.
Cured-in-place liners are generally specified with a design life in the region of 50 years, comparable to new pipe. The practical caveat is that a liner only protects the section it covers — defects beyond either end of the relined run are untouched, which is why the survey matters.
No, and be cautious of anyone who says otherwise. Relining needs a pipe that is structurally continuous and reasonably round. Full collapses, severe crushing and significant back-falls need excavation. Very tight bends and some junction configurations also rule it out.
Frequently, once reinstatement is counted. The excavation itself may be cheaper on a shallow, accessible run under a lawn. But when the drain runs under a concrete driveway, a deck, or mature landscaping, the cost of putting things back often exceeds the difference — which is where relining wins.
Repairing an existing private drain generally does not require building consent, but work affecting the public network, new connections, or building over a public line can require engineering approval from Auckland Council. We will tell you if your job falls into that category before quoting.
Yes. Repair and relining carry a workmanship warranty, with the length stated in your written quote. It covers our workmanship — not new blockages caused by what goes down the drain, nor failure of a different section we did not work on. Your rights under the Consumer Guarantees Act apply regardless.
A short patch liner can be a single day. A full lateral reline is typically one to two days. An excavated repair depends on depth, access and reinstatement — a shallow section can be done in a day, while a deep repair under a driveway with concrete reinstatement runs longer. The quote should give you a timeframe.
Sometimes that genuinely is the right call, and we will say so. If the intrusion is minor, the drain rarely actually blocks, or you are selling shortly, periodic clearing may be the sensible economic choice. If you are clearing the same drain every year or two, do the arithmetic over five years before dismissing the repair.
We cover the whole region. Pick your suburb for local detail.
Tell us what the drain is doing. We will tell you whether this is the service you need, and what it should cost.