Why it pays to ask the right questions
Drainage work is not the sort of trade you want to get wrong. A poorly installed foul water or stormwater system can lead to blockages, odours, pooling, dampness, foundation issues and expensive call-backs. In New Zealand, drainlaying is restricted work, so the person doing the job should be appropriately licensed and experienced for the type of work you need.
Before you accept a quote, ask a drainlayer a few straightforward questions. Their answers will tell you far more than a sales pitch ever will: whether they understand local council requirements, whether they work neatly and safely, how they handle unexpected ground conditions, and whether their pricing is realistic for the job.
The checklist below is designed for New Zealand homeowners, whether you are dealing with a blocked or damaged drain, replacing an old clay line, adding a new bathroom, or sorting drainage for a renovation.
1) Are you licensed to do this work?
Start with the most important question: **“Are you licensed to carry out this drainlaying work?”**
In New Zealand, drainlaying is restricted work and is regulated through the **Plumbers, Gasfitters and Drainlayers Board (PGDB)**. Ask for the drainlayer’s licence number and check that it is current. Don’t just take “I’m qualified” as enough.
Ask:
- What is your drainlaying licence number? - Is your licence current and in good standing? - Will you personally do the work, or will someone else on your team carry it out? - If other trades are involved, who is responsible for coordinating them?
If the job also involves plumbing, gasfitting, electrical work or structural changes, those trades have their own licensing rules. For example, electrical work is regulated by the **Electrical Workers Registration Board (EWRB)**, and building work may need to be done by a licensed building practitioner (LBP) and/or require a building consent from your local council.
2) Have you done this type of drainlaying job before?
Drainlaying is broad. Installing a new stormwater soak pit is not the same as replacing an old shared sewer line or dealing with root intrusion under an existing driveway.
Ask:
- Have you completed similar jobs in homes like mine? - How many years have you been drainlaying? - Do you regularly handle repairs, replacements, or new installations? - Have you worked on older Kiwi homes, steep sites, clay soil, or coastal properties before?
A good drainlayer should be able to explain the likely challenges for your site. In many parts of New Zealand, older suburbs have ageing clay or earthenware pipes, while newer subdivisions may have plastic pipework but tighter compliance requirements. If your property is on a sloping section, has a high water table, or tends to get waterlogged in winter, that matters too.
3) Have you inspected the site in person?
A reliable quote should be based on a proper site visit, not just a quick phone estimate.
Ask:
- Have you been to the property to inspect the existing drainage? - Will you check the likely pipe route, levels, access and soil conditions? - Do you need to use a camera inspection or locate the line first? - What hidden problems might change the cost?
For drainage work, access can make a big difference. A narrow side path, deck, concrete driveway, retaining wall or mature landscaping may add labour and reinstatement costs. A proper site visit also helps the drainlayer spot issues with falls, crossings, soakage, nearby services and stormwater discharge points.
4) What exactly is included in your quote?
This is one of the most important questions to ask. A quote that looks cheap can become expensive if it excludes excavation, disposal, traffic management, council paperwork or site reinstatement.
Ask for a written quote that clearly sets out:
- Labour - Materials and pipe type - Excavation and backfill - Machine hire, if needed - Disposal of spoil - Camera inspection or location work - Council inspection fees, if applicable - Traffic management or access control, if needed - Reinstatement of paving, lawns or concrete - GST
It helps to ask:
- What is included and what is excluded? - Are there any provisional sums or estimated items? - What could make the price increase? - Do you charge call-out fees or minimum charges?
Helpful quote comparison checklist
| What to compare | Why it matters | |---|---| | Licence and experience | Confirms the person is qualified for restricted work | | Scope of work | Ensures all tradespeople are quoting on the same job | | Materials specified | Different pipe systems and fittings affect cost and durability | | Exclusions | Avoids surprise extras for digging, disposal or reinstatement | | Timeframe | Helps you compare urgency and scheduling realistically | | Warranty/guarantee | Shows what support you get if something goes wrong | | Payment terms | Protects you from paying too much upfront |
If you get three quotes, make sure they are comparable. A quote for a repair is not the same as a quote for a full replacement with new access points and council compliance work.
5) Do I need council consent or inspections for this job?
Not every drainage job needs consent, but some do. Ask the drainlayer whether the work is likely to require approval from your local council or whether it can be completed as maintenance or like-for-like replacement.
Ask:
- Does this job need a building consent, drainage approval or inspection? - Will you organise the paperwork, or do I need to do that? - Have you dealt with my local council before? - Will you provide the documents I need for my records?
In New Zealand, the rules can depend on the scope of work, whether the work affects existing plumbing or drainage infrastructure, and whether the job is part of a wider renovation. If the project is connected to a kitchen, bathroom or laundry upgrade, there may be additional compliance requirements. A good drainlayer should be able to tell you when to check with the council rather than guessing.
6) How long will the job take, and when can you start?
Drainage work is often weather-dependent, especially in winter or after periods of heavy rain. Wet ground can slow excavation and create reinstatement issues.
Ask:
- When could you start? - How long will the job take? - What factors could delay it? - Will you keep the site safe and usable while work is underway? - Do you work in bad weather, or will rain push the schedule out?
Ask for a realistic programme rather than a best-case promise. A small blocked drain may be completed in a day, while a full replacement, camera diagnosis and reinstatement can take longer. If the drainlayer needs to coordinate with a plumber, builder, concreter or council inspector, allow for that in the schedule.
7) Who will actually be on site?
Sometimes the person who quotes the work is not the person doing it. That is not necessarily a problem, but you should know who is responsible.
Ask:
- Will you do the job yourself or supervise others? - Are your staff or subcontractors qualified for the tasks they’ll perform? - Who is my main contact during the job? - Will the same team return if there’s a follow-up issue?
You want confidence that the work won’t be handed off to someone inexperienced without supervision. If machinery is involved, ask who operates it and whether they are trained to work safely around services and structures.
8) Are you insured?
Insurance is essential when excavation, underground services and water damage are involved. If a mistake damages your driveway, fence, foundations or neighbouring property, you need to know there is cover in place.
Ask:
- Do you have public liability insurance? - Are you insured for excavation and drainage work? - Do you carry cover for your tools and equipment? - Are your subcontractors insured as well?
If the drainlayer is unwilling to discuss insurance, that is a warning sign. Ask for proof if needed. Also check your own home insurance policy, especially if the work involves significant digging or a temporary change to drainage around the house.
9) What warranty or guarantee do you offer?
A solid drainlayer should stand behind their work.
Ask:
- What warranty do you provide on workmanship? - How long does it last? - Are materials covered by the manufacturer’s warranty? - What is excluded from the guarantee? - If there’s a problem, how do I get it fixed?
Be wary of vague promises like “we’ll sort it if anything happens”. Ask for the warranty or guarantee in writing. It should explain whether the cover applies to workmanship only, materials only, or both. It should also spell out what happens if the issue is caused by tree roots, ground movement, council infrastructure, or misuse after the job is complete.
10) Can you provide references or recent examples of similar work?
References matter, especially for drainage work that is buried underground and hard for a homeowner to inspect once complete.
Ask:
- Can you provide recent references from similar jobs? - Do you have photos of completed drainage projects? - Can I see examples of work on properties similar to mine? - Do you have online reviews from New Zealand customers?
A good drainlayer should be happy to point to work they are proud of. If possible, ask for recent references rather than testimonials from years ago. Similar properties and similar problems are more useful than generic praise.
11) How will you communicate during the job?
Clear communication avoids stress and budget blowouts.
Ask:
- How will you update me if the job changes? - Do you call before extra work is carried out? - Will you send progress photos if I’m not home? - Who approves variations?
This is especially important if you are not on site, if the work is part of a rental property repair, or if the job may uncover hidden damage. Agree in advance that no extras are done without your approval unless they are urgent for safety.
12) What should I do before work starts?
A professional drainlayer should also tell you what you need to prepare.
Ask:
- Do I need to locate boundary pegs, services or access points? - Should I clear the area or move vehicles? - Will you need water or power access? - Is there anything I should do to protect pets, gardens or outdoor structures?
If the work involves digging near other services, confirm how underground utilities will be identified before excavation begins. Safe site preparation protects everyone and can reduce delays.
Red flags to watch for
Be cautious if a drainlayer:
- cannot produce a current licence number - only gives verbal pricing - avoids site visits - refuses to explain exclusions - pressures you to start immediately - asks for a large cash payment upfront without a clear reason - has no insurance or cannot show evidence of it - seems vague about who will do the work or what happens if problems arise
If anything feels off, get another quote. A rushed decision on drainage work can cost far more than waiting a few extra days for the right person.
A simple checklist you can use before hiring
Before you sign anything, make sure you can answer “yes” to these:
- Have I checked the drainlayer’s licence? - Have I confirmed they’ve done similar work before? - Have I received a written quote with inclusions and exclusions? - Have I asked whether council consent or inspections are needed? - Do I know the start date and expected duration? - Have I confirmed insurance and warranty details? - Have I asked for references or examples of recent work? - Do I understand how variations will be approved?
Final advice
The best drainlayer for your job is not always the cheapest. Look for someone who is properly licensed, transparent about pricing, realistic about timeframes and comfortable explaining the work in plain English. If they welcome your questions and answer them clearly, that is usually a good sign.
For New Zealand homeowners, a careful hiring process is worth the effort. Drainage work is often hidden once complete, so the quality of the person you hire matters just as much as the quality of the materials. Ask the questions first, compare written quotes, and choose the drainlayer who gives you confidence as well as a fair price.