There's a new class of tradesmen cropping up in Auckland - fix-it men.
No, not handymen who do odd jobs round the house - tradesmen who fix mistakes by the "cowboys" originally hired to do a professional job.
Jayson Thomas is manager of the investigative team for the Plumbers, Gasfitters and Drainlayers Board. A former policeman, he now heads a small staff of six investigators and technical advisers.
What do they investigate? Shoddy work performed by tradesmen who are not licensed - popularly known as cowboys - and work done by inexperienced tradesmen who are supposed to be supervised when working on a project...but often aren't. They also check up on tradesmen who were once licensed but have let it lapse.
It's in this context that Thomas and his investigators have noticed a new trend in Auckland - a thriving industry which has sprung out of the fact many cowboys are botching jobs luckless homeowners have paid for and then have to pay out again to fix them.
"I have spoken to people who recently have ceased to do any commercial work themselves. Instead, they just do maintenance work - but what that really means is they follow the people who are doing the original work and do fix-ups.
"For one of the guys I spoke to, that was his entire business - fixing other people's shoddy work - and he was absolutely flat out. It is one measure of just how many cowboys there are out there these days."
The main reason for this increase in the cowboy population is the building boom in areas like Auckland and Queenstown and other parts of the South Island.
Thomas says: "It's a buoyant construction market; some people see a chance to make easy money."
PGDB CEO Martin Sawyers says earthquake zones had been a target: "After the Christchurch earthquakes in 2010 and 2011, there were instances of people offering plumbing services when untrained and unlicensed - and we issued a warning to that end when the Kaikoura quake happened."
Now numbers of cowboys being detected and prosecuted are rising "because we are getting better [at detecting them]."
Thomas says a key tool is the Report A Cowboy (RAC) app launched last year, downloadable from the PGDB website. There are no figures available to compare from previous years but 126 complaints were laid over the app last year and 15 so far this year, with over 10,000 downloads of the app. Just under half the complaints involved allegedly unauthorised plumbers.
"Even if the information we receive through the app and other methods does not lead to a prosecution, it is an excellent intelligence-gathering tool," says Thomas. "It allows us to put a picture together involving a firm or an individual."
Thomas and his investigators can then "raid" projects where they have heard unlicensed operators may be carrying out illegal work.
Thomas doesn't like to call such surprise visits "raids" as he says they are generally low-key affairs. However, the investigators' work has enabled them to recognise a building sector under pressure, taking short cuts and sometimes exploiting workers.
"No one is making any excuses - plumbing, gasfitting and drainlaying has to be done by trained and licensed professionals for very good reasons," says Thomas. "But everyone [in the building sector] is feeling the pressure, particularly in Auckland and Queenstown, to build more and more. That creates a strong demand for contractors."
What happens next can cause problems. Thomas says some contractors hire unlicensed workers or gain an exemption to have unlicensed workers operating under the close supervision of a licensed tradesman.
In reality, the tradesman will often be away at another site because of the pressure of business - leaving behind unlicensed workers who Thomas says don't know what they are doing and who sometimes cause "absolute bedlam".
The worst case he has seen so far was in Christchurch where a drainlaying job went badly wrong. The workers had over-excavated the site, meaning the homeowners couldn't lay the tar-sealed driveway they wanted but instead had to pay out for a much more expensive reinforced concrete drive.
Even worse, the work meant the homeowners couldn't use their shower or toilet. The tradesman told the owners to use the neighbour's (instead of connecting up the drains every night when work finished) - but the neighbours were similarly unable to use their toilet.
"There was a part-timer and a first-year apprentice in charge of the job - the main guy spent most of his time at another site; this job was so bad the tradies got in to fix things said originally they didn't want to touch it."