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Plumber or Drainlayer: Who Should You Call?

TopChoice

Thursday 18 June 2026, 10:23AM

By TopChoice

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Plumber or Drainlayer: Who Should You Call?
Plumber or Drainlayer: Who Should You Call? Credit: TopChoice NZ

When water starts appearing where it should not, a toilet refuses to drain, or an unpleasant smell begins coming from outside, most homeowners know they need help — but they may not know whether to call a plumber or a drainlayer.

The two trades are closely connected, and many businesses employ professionals qualified in both areas. However, plumbers and drainlayers generally work on different parts of a property’s water and wastewater systems.

Understanding the difference can help you contact the right person sooner, avoid unnecessary call-out costs and get the problem fixed properly.

TopChoice helps New Zealand homeowners compare trusted local service businesses, but before choosing someone, it helps to understand which trade your job is likely to require.

What Does a Plumber Do?

Plumbers generally work on the water supply, pipework, fixtures and appliances located within or immediately around a building.

You will usually need a plumber for problems involving:

Leaking taps or pipes

Burst water pipes

Toilets that will not flush properly

Blocked sinks, showers and basins

Low or inconsistent water pressure

Hot water cylinder problems

Bathroom and kitchen renovations

Installing taps, toilets, showers and other fixtures

Dishwasher or washing machine connections

General plumbing maintenance

A plumber is normally the first person to call when the problem affects a fixture inside your home.

For example, if water is leaking underneath the kitchen sink, your shower has lost pressure or your hot water cylinder is not working, the issue is most likely within a plumber’s area of expertise.

Homeowners looking for help can browse recommended plumbers across New Zealand and compare local options by location.

What Does a Drainlayer Do?

Drainlayers generally work on underground pipes and drainage systems that carry wastewater or stormwater away from a property.

Their work can include:

Installing new wastewater drains

Repairing cracked or collapsed underground pipes

Replacing damaged drains

Connecting drainage systems to approved disposal points

Installing stormwater drainage

Repairing sewer lines

Investigating recurring underground blockages

Working on drainage for new homes and extensions

Excavating and replacing damaged sections of pipe

A drainlayer may be required when the problem is below ground, affects the main drainage system or involves replacing or installing underground pipework.

Typical signs of an underground drainage problem include wastewater backing up through several fixtures, persistent sewage smells, wet or sunken areas in the garden and blockages that continue returning after being cleared.

TopChoice provides location-based lists of recommended drainlayers in New Zealand to help property owners find suitable local businesses.

Who Should You Call for a Blocked Drain?

Blocked drains are where the distinction becomes less obvious.

A blockage affecting a single sink, shower or toilet may be caused by a local plumbing problem. In this situation, a plumber may be the best first call.

However, the issue may involve the underground drainage system when:

Several fixtures are blocked at the same time

Toilets gurgle when another fixture is used

Wastewater is backing up through floor drains

The same blockage keeps returning

Sewage is appearing outside

There are signs of a broken or collapsed pipe

Tree roots may have entered an underground drain

Many plumbing and drainage companies offer drain unblocking services and employ both plumbers and drainlayers. When calling, explain exactly what is happening and ask whether the business is equipped to diagnose and repair underground drainage faults if required.

What About Leaking Pipes?

The location of the leak usually determines which trade you need.

A plumber will generally handle leaking water-supply pipes, taps, toilets, hot water systems and pipework inside the building.

A drainlayer may be required if the leak comes from a damaged wastewater or stormwater drain beneath the ground.

Water appearing in the garden does not automatically mean the problem is drainage-related. It could also come from a leaking underground water-supply pipe. A qualified professional may need to inspect the area before confirming the cause.

When Should You Call a Plumber First?

Contact a plumber first when the problem involves:

A tap, toilet, shower or basin

Hot or cold water supply

A hot water cylinder

A visible pipe leak

Plumbing fixtures inside the home

Bathroom or kitchen plumbing

A blockage limited to one fixture

A plumber may also be able to identify when a problem extends into the underground drainage system and recommend a drainlayer where necessary.

When Should You Call a Drainlayer First?

A drainlayer is more likely to be required when:

The problem affects the main sewer or wastewater line

Several drains are backing up simultaneously

Wastewater is surfacing outside

An underground drain is cracked or collapsed

New drainage needs to be installed

Stormwater is not draining correctly

A recurring blockage may involve tree roots or damaged pipes

Excavation is needed to access the drainage system

Drainage problems should not be ignored. Wastewater leaks and damaged drains can affect the surrounding ground, create unpleasant odours and potentially cause further damage to the property.

Some Tradespeople Are Qualified in Both Areas

Many New Zealand businesses offer both plumbing and drainlaying services. This can be particularly useful when the cause of the problem is not immediately clear.

For example, a blocked toilet may initially appear to be a simple plumbing problem. Further investigation may reveal that the blockage is caused by a damaged underground drain.

Choosing a business with access to both plumbing and drainlaying expertise can reduce the need to organise separate contractors.

However, homeowners should still check that the person carrying out restricted work holds the appropriate current authorisation for that type of work.

Questions to Ask Before Booking

Before arranging a call-out, give the business as much information as possible.

Useful questions include:

Do you handle both plumbing and underground drainage work?

Is the person attending licensed for the work required?

Do you have equipment for inspecting blocked or damaged drains?

Is there a separate call-out fee?

Are there additional charges for after-hours work?

Will you provide a quote before carrying out major repairs?

Can you repair the problem if excavation is required?

Photos, videos and a clear description of the symptoms may help the business decide which team member and equipment to send.

What to Do in an Emergency

For a burst water pipe or major internal leak, turn off the property’s water supply if it is safe to do so. Avoid electrical fittings and appliances near the affected area and contact an emergency plumber.

For a sewage backup, stop using toilets, sinks, showers and appliances that discharge wastewater. Keep people and pets away from contaminated areas and contact a plumbing or drainage professional promptly.

Do not attempt to excavate or repair underground drainage pipes without the correct knowledge and authorisation.

Choosing the Right Trade

As a general rule, plumbers work on water supply, fixtures, hot water systems and plumbing within the building. Drainlayers work mainly on underground wastewater and stormwater drainage.

There is some overlap, particularly with blocked drains, and many companies provide both services. The important thing is to describe the problem clearly and confirm that the business has the appropriate expertise and licensing before work begins.

Calling the right professional at the beginning can make the repair quicker, safer and considerably less stressful.