Drainage – Drainlaying And Subsoil System Installers



Besides creating a warm, dry and comfortable home your next most important part of your home is your drainage. We often take for granted what happens to the waste water when we turn on the shower, load and start the dishwasher, turn on the washing machine and don’t even give it a cursory thought.
As long as the drains are functioning we tend not to think about it. It is only when we encounter a problem that we fly into panic mode. There are many factors that can cause your house drainage system to fail. Usually grease and fat, corrosion, inadequate drainage, tree roots, and subsidence are the culprits that cause your drains to fail.
A working residential sewer system is critical to health, environment and life style. It is essential to have your house drainage system checked and cleaned ensuring the pipes are in good working condition at all times.
Rain water – commonly referred to as surface water – needs a good surface drainage system run off to prevent pollution and control flooding. Surface water flooding happens when the drainage system is overloaded.


What could increase my building costs?

  • If you are building below the rise of your road you may require a sewer pump which is used to pump lower level sewage upstream to a point of gravitational fall.
  • Unfortunately, many Auckland suburbs still have a combined storm water and sewer system, and so a new build will need to provide a backflow of detention solution to satisfy the council.
  • Check the LIM report – Does your site have a public drain running through it? If it does then you need to allow for extra cost to possibly divert or bridge over the drainage line.

What do we look for if we’re buying an existing home or renovating?

  • Repairing an existing sewer line can be very expensive and you want to make sure you don’t get caught out, so, before purchasing add a clause to you Sale & Purchase Agreement to allow you time to get a CCTV inspection done to ensure all existing sewer lines are in good working order
  • In older suburbs your sewer line could be made of Verified clay or “earthenware pipe”. These products tend to degrade and are susceptible to tree root damage and collapse.

Commercial Drainage

Commercial drainage systems can be very challenging. For one, the size of them is nothing like a residential system and then the demands placed on the system are very high.
Commercial drainage commonly involves depths which exceed 1.5 meters requiring shoring capabilities and diggers that reach that kind of depth. Commercial drainage also involves handling heavy pipework made of concrete, wing-walls including large scale commercial chambers, cess pits and management devices. Pipe sizes can vary from 225mm to 1.5 meters.


Commercial drainage requires the drainlayers to be registered with the Plumbers, Gas Fitters and Drainlayers Board as certified drainlayers. In addition to this, if you are contemplating public works then the drainlayers are also required to be registered with the local Council and water authority.

The Health and Safety law in New Zealand is very tight and every company is required to have a health and safety policy in place. By employing health and safety conscience drainlayers you will limit your liability and ensure a smooth process if an accident takes place.
Professional maintenance of your commercial drainage system is critical to your facility’s operation. It can keep your plumbing system running smoothly and help save money in the long run.
Having a regular maintenance plan will uncover minor issues before they turn into expensive repairs that can unexpectedly impact your bottom line. It will also ensure that your building is safe and sanitary and protect your investment.