While more than two-thirds (68.8%) say they face the problem of competing with unqualified plumbers who can do the job cheaper, HVP Mag reported.

Half of those surveyed (52.2%) also complained that they are fixing people’s DIY mistakes daily. Only 15% of these plumbers said they don’t have to deal with poor work from a previous plumber or faulty DIY each month.

The remaining 85% of these plumbers spent one or more jobs each month fixing the poor work of others. Of those, 22.9% (or two in every five plumbers) do more than five jobs each month fixing other plumbers’ poor work.

The top three most common faults that need to be fixed because of poor work are leaks (28.5%), toilets or sanitation (21.5%) and the wrong fittings or poor-quality fittings (16.3%).

Julie Spinks, managing director of Water Regs UK, said: “These findings show that consumers are at risk of paying more than they need to and risk damaging their properties when plumbing jobs go wrong.

“Customers are left with higher bills than they anticipated when they can least afford it. This also increases waiting times for everybody who needs plumbing services.

“And of course, this is potentially damaging to the overall reputation of the industry. It casts a shadow on most plumbers who are honest, genuine and hardworking.

“All of these are good reasons for customers to choose a qualified plumber through the WaterSafe approval scheme. Accredited individuals and organisations have been checked to make sure they are suitably qualified and insured.

“Each year a proportion of members are audited against the water fittings regulations. Those approved are required to issue a certificate of conformity against the regulations, to provide their customers assurance.”