Few things derail a house sale as quietly as drainage. A buyer’s builder notices a damp subfloor, a pre-purchase drain camera finds a cracked pipe, or a council file shows unconsented stormwater work, and suddenly a sale that looked done is back in negotiation. For separating owners who need the proceeds to set up two new homes, a delayed settlement can mean extra rent, bridging costs and a lot of stress. Understanding the common drainage issues before listing gives you a better chance of a clean run through to settlement.
Why drainage gets picked up late
Drains are out of sight, and many owners have never thought about them unless something has backed up. Buyers, however, are increasingly cautious. In many parts of New Zealand, especially older suburbs with clay or earthenware pipes, it has become common for buyers to commission a CCTV drain inspection as a condition of the sale, alongside the usual building report.
That inspection can reveal problems the owners had no idea about:
- Tree roots growing into joints and partially blocking the line.
- Cracked or collapsed sections of older pipe.
- Sagging pipes, often called “bellies”, where water and waste sit rather than flowing away.
- Stormwater connected to the wastewater system, or the other way round.
- Soak holes or stormwater outlets that no longer work properly.
Any of these can prompt a buyer to ask for repairs, a price reduction or more time, all of which can push settlement back by weeks.
Warning signs worth checking now
You can pick up a lot simply by paying attention around the house and section. Common warning signs include:
- Gurgling sounds from sinks or the toilet after a flush.
- Slow drains in more than one fixture at the same time.
- Bad smells near gully traps or in the garden.
- Lush, unusually green patches of lawn along the line of a sewer pipe.
- Water pooling against the foundations or under the house after rain.
- Gully traps overflowing during heavy downpours.
Hamilton and much of the Waikato have flat, low-lying areas where heavy rain struggles to drain away, and older suburbs with ageing pipework. Properties with large established trees near drains are also at higher risk of root intrusion.
Getting ahead with your own inspection
A pre-listing drain inspection is often modest in cost compared with the risk of a failed or delayed sale. A CCTV inspection typically costs a few hundred dollars depending on access and the length of pipe, and it gives both owners clear information to make decisions with before buyers are involved.
If you are in the Waikato, local knowledge helps. Hamilton drainage specialists will be familiar with the soils, older pipe materials and council requirements in the area. Ask for the footage and a written summary, so you can share it with an agent and, if needed, with prospective buyers.
It is also worth requesting the property file from the council. It can show the drainage plans the council holds and whether any past work was consented. Discrepancies between what is on file and what is actually in the ground are a common source of late questions from buyers’ advisers.
Fix, disclose or negotiate
Once you know what is going on underground, there are a few broad options:
- Repair before listing. Clearing roots, relining a section of pipe or replacing a short length can cost from several hundred to several thousand dollars. Larger replacements cost more, especially if they run under driveways or paths.
- Disclose and price it in. If repairs are expensive or would take a long time, providing the report upfront lets buyers factor it into their offers rather than discovering it during due diligence.
- Agree a fix as part of the sale. Sometimes repairs are completed between unconditional and settlement, though this needs careful coordination.
Each route has financial and legal implications, particularly around disclosure and how costs are shared between owners. Get independent advice and agree the plan in writing with the other owner. A clear agreement now is far easier than a dispute mid-settlement.
Protecting the settlement date
Settlement delays ripple outwards. They can affect rental start dates, children’s schooling, moving company bookings and bridging finance. To protect the date, aim to have drainage information, building reports and any repair invoices ready before the first open home. The fewer surprises buyers find, the less likely they are to ask for extensions or conditions that stretch the timeline.
Keep the section in good shape during the marketing period too. Clear leaves from gully traps and gutters before forecast heavy rain, and avoid planting anything new near known pipe runs. A gully trap overflowing during a wet Saturday open home is the kind of image that sticks with buyers and invites closer scrutiny.
Frequently asked questions
Do buyers in New Zealand usually get drain inspections? It is increasingly common, particularly for older homes. Many buyers add a drain inspection alongside a building report as a condition of their offer.
How much does it cost to fix a broken drain? Small repairs or root clearing may cost a few hundred dollars. Relining or replacing longer sections can run into the thousands, and it varies with depth, access and pipe length.
Can drainage issues actually stop a settlement? Serious unresolved issues can lead buyers to withdraw during the conditional period or ask for changes to the agreement, which may delay settlement. Getting information early reduces that risk.