In-Ground Copper Pipe Leak in Roseville: A Pinhole in Old Type C Pipe

The situation

A homeowner in Roseville got in touch about a wet patch that had appeared in the front garden. It wasn’t the first time; the property had a history of in-ground leaks, so the client already suspected another one before we arrived.

The first check on any suspected in-ground leak is the water meter, not a shovel. With every tap and appliance in the house turned off, a meter that’s still ticking over confirms water is escaping somewhere in the buried pipework, before anyone digs a single hole. That’s what we found here, so we knew we were chasing a real leak rather than a drainage or garden bed issue.

What we found

In-ground leaks can be genuinely hard to pin down. Water doesn’t always surface directly above the fault, it can travel through the soil and show up metres away. We were fortunate on this job to have a strong indication of where the ground was wettest, which gave us a starting point to expose the plumbing and follow it in from there.

Once we’d traced the line and exposed the pipe at the problem area, the fault was clear: water was spraying out through a pinhole. A closer look at the pipe itself explained why. It was Type C copper, a thinner-walled, cheaper copper that used to be installed to save money on the original job.

That cost-cutting is exactly what was catching up with this homeowner decades later. Type C’s thin wall means it has very little tolerance for anything pressing against it or striking it, a rock it was laid against, or even a shovel from a past bit of garden work, and any point of contact like that can eventually wear through and let go.

Old plumbing shortcuts don’t disappear, they just wait. Type C copper was laid to save money on the job, and it’s the homeowner who ends up paying for it years later.

The fix

The repair itself was straightforward once the pinhole was exposed: cut out the worn section of Type C pipe and replace it with a new section of Type B copper, the thicker-walled standard now used for underground water supply runs. Type B is built to handle the conditions Type C wasn’t, resisting the kind of point loads and general wear that comes with being buried in the ground.

With the new section in and joined, we turned the water back on to the household and confirmed the leak was gone before packing up.

The outcome

Water was back on and the leak fully repaired in the one visit, the same day it was called in. For a leak that had already been a repeat issue at the property, having it found and fixed without a second call-out was exactly what the customer wanted, and they were delighted with the result.

The section we replaced is sound, but it’s worth being upfront about the rest of the run: if the pipe from the water meter to the house is still the original Type C copper, more leaks like this one are likely over time, since the pipe itself hasn’t changed, only the section that failed first. The longer-term fix for a property with this history is replacing that full run with Type B copper, rather than patching each new pinhole as it turns up.

Wet patch in the garden, or a water meter that won’t stop ticking? Our leak repairs team tests the meter and traces in-ground leaks before we dig, and covers Roseville and the rest of the North Shore. For burst or failing pipework more broadly, see our burst pipe repairs page.