Drainlaying in Christchurch

Drainlaying is not the same job as clearing a blockage

Most people meet a drainlayer on a bad day, when something is blocked and it needs to stop being blocked. That is drain clearing, and it is the smaller half of the trade. Drainlaying is the other half: laying the new line, making the connection, and taking out the length that keeps failing so it stops being an annual problem.

The difference matters because clearing a blockage treats the symptom. If a drain has a dip in it, a broken joint or roots through a clay pipe, clearing it buys months. Relaying that length is what ends it. We put a camera down first so you are choosing between the two on evidence rather than on a guess, and so you are not paying to dig in the wrong place.

Drainlaying is certified work. Sanitary drainage has to be done and signed off by a certifying drainlayer, which is a licence rather than a job title, and the council wants that sign off on record. We are PGDB certified, so consented work, new connections and anything an insurer or a buyer will later ask about is covered properly.

• New drains, new builds and connections to the main
• Relaying failed and earthquake damaged lines
• Pressure sewer systems across Selwyn
• PGDB certified, so the sign off is covered

What a drainlaying job involves, start to finish

It starts with levels. Before a trench is dug we know where the drain begins, where it has to finish and how much fall there is between the two. Then the run is marked out, buried services are located, and the trench is dug to depth.

The pipe is laid on a prepared bed so it is supported along its whole length, each joint is sealed, and the fall is checked as the line goes in. Where the work is under a building consent it is inspected before it is covered. Then the trench is backfilled in layers and the surface is reinstated.

Connections to the council main

A new house, a subdivided section or a replacement line all end at the same place, which is the connection to the council system. That connection is controlled work. In Christchurch it has to be done by a drainlayer the council has authorised, and we are CCC authorised.

We deal with the council side of it as part of the job, so you are not left working out which form goes where.

What goes in the ground now

The earthenware pipe under many older Christchurch homes came in short lengths with a joint every metre or so. Modern drains are laid in PVC, in long lengths with sealed joints. Fewer joints and tighter joints mean fewer ways in for tree roots and fewer places for a line to pull apart.

That is why relaying an old run is often better value than patching it. If you are not sure which you need, the drain repairs page walks through how we decide.

Stormwater is drainlaying too

Drainlaying is not only sewers. Channel drains across a driveway, sumps, subsoil drains under a wet lawn and soak pits are all laid drains, and they are a large part of our work for homeowners. There is more on that under stormwater and yard drainage.