The Master Plumbers, Gasfitters and Drainlayers Society feels vindicated by a report by Auditor-General into how the Plumbers, Gasfitters and Drainlayers Board trains tradespeople.
The society represents 7000 of the 10,000 registered tradesmen in the country.
President Dave Strong says the society lobbied hard for the problems to be recognised in the first place.
The Auditor-General has made 15 recommendations about the board's operations.
Lyn Provost says long-term monitoring of the board should continue, as poor work could endanger people and property.
Her inquiry followed complaints that the board was dysfunctional and out of touch with its members.
Acting registrar Kern U'ren says the board has already made changes since the inquiry began in 2008 and many of the recommendations have already been put in place.
Ms Provost described the sector as characterised by suspicion and discontent.
While changes already made by the board are seen as a good beginning, Ms Provost said they are not yet sufficient and the board will need long-term monitoring.
