Around one in 10 households in Wales have fallen victim to rogue traders in the last five years.

This has led to advice for homeowners to protect themselves from poor plumbing.

Research by WaterSafe, the national register of approved plumbers, shows that almost 10 per cent of Welsh households have had to employ a second professional to rectify the damage caused by rogue traders.

The most common reasons for needing a second professional were failure to solve the original issue or causing a water leak, both at 41 per cent.

In a third of cases, pipework was wrongly connected.

To help homeowners avoid rogue traders, WaterSafe suggests several tips.

These include using an approved contractor, asking for ID, being wary of scare tactics, get written quotes, and ensuring a work completion certificate is received.

Julie Spinks, director of WaterSafe, said: "While 90 per cent of our survey respondents felt it should be compulsory for plumbers to hold minimum qualifications and be on an official register, there is no legal requirement to do so – anyone can call themselves a plumber, regardless of their experience or qualifications.

"WaterSafe has almost 8,000 qualified contractors and our plumbers are trained in the water regulations, hold public liability insurance, and have appropriate complaint procedures – just in case."

Kevin Wellman, chief executive of the Chartered Institute of Plumbing and Heating Engineering (CIPHE), added: "Falling foul of a rogue trader can not only be distressing and costly, but poses a real threat to the quality of your drinking water.

"If plumbing work isn’t carried out correctly, it’s easy to cause contamination or leaks.

"Choosing an approved contractor makes sure all work adheres to the Water Supply (Water Fittings) Regulations which keep tap water safe."

For more advice and to find a list of approved contractors, visit the WaterSafe website.