Which? uses cookies to improve our sites and by continuing you agree to our cookies policy

DIY Disasters

By Rebecca Milligan

DIY sounds like a great idea - but the reality can be a lot messier, costlier and even more dangerous than you might expect. This guide explores what can go wrong, and how to avoid expensive mistakes.
DIY disaster man holding electrical cable with burns on his shirt, plus smoke blackened face

Despite seeming like a money saver, DIY can end up costing more than you think. A Halfords survey from 2014 found householders and motorists pay out an estimated £300m a year to professionals to fix the cost of their mistakes. A 2016 survey for JJ Roofing Supplies found that half of their respondents argued with their partner about DIY tasks and, in extreme situations, 9% had needed medical help as a result of their DIY activity.

If you’d like help with home or motor maintenance, Which? Trusted Traders has endorsed professional tradespeople who can take the strain.

Electrical blunders

Our Which? Trusted traders have reported getting a lot of custom from people who’ve had a go themselves, and then need a professional to put things right. For example, Chris Gordon from Electricians in Reading told us they get a lot of emergency call-outs from people who drill through wires when they’re trying to put up pictures.

Justin Bucknell, of Justin Bucknell Electrical, told us this horror story: ‘When we arrived to test a property with an electric shower, we found it was being fed by an undersized cable. Slowly, with every use, it had started to get so hot it was melting the outer PVC, and then started to heat the outer casing for the shower. This had opened up a very small gap, allowing water to pass on to the bare cable that was just behind the cover!

‘The potential for electric shock was probably the worst we’ve seen – we’re very glad we were able to spot it and get things sorted.’

Avoid disaster:

  • When drilling holes in your walls, check the location of cables first. You can buy a simple cable and wire detector from DIY stores.

  • Always use an NICEIC or ELECSA qualified electrician to undertake your electrical installation projects.

  • Campaigning charity Electrical Safety First recommends getting your electrics checked every five years in a private property to ensure they are safe.

Find out more about why every home needs an electrical-installation condition report. Read on for more DIY disasters.

Plumbing horror stories

Plumbing is one area where you really need to know what you’re doing. There are countless stories of washing-machine hoses being plumbed in incorrectly, leading to soggy floors or ruined smalls. But it can be more extreme.

Kris Barry, from Absolute Bristol plumbers, told us that calls from DIYers made up a large part of his business. ‘Having a go yourself can end up costing a lot of money in the long run – what might be a small job for a professional, might not be for you,’ he said. ‘I’ve had a call this evening, where a customer tried to sort out their U-bend themselves. They now can’t use their kitchen sink because they took it off themselves and it has broken.’

It gets worse. He told us: ‘Another time, a lady decided to disconnect the trap (a water filled area of pipe that stops waste gases entering the room) on her bath to try to clean it out. She couldn’t get it back on again, and had a bath full of water because she was in the middle of cleaning her bathroom. So when she went to let the water go, it was going through the ceiling … and there was a load of damage to the house.’

Avoid disaster:

  • Use a Which? Trusted Traders-endorsed plumber in your area

  • Ensure you know where your stopcock is, so you can turn water off at the mains before starting any plumbing job

  • Don’t try to force pipes and connectors together – it may well damage them.

Check our 10 expert tips on how to look after your plumbing system for plumbing advice.

Central-heating disasters

The danger ratio goes up a level when you bring gas into the equation. Get it wrong and it can be fatal. Gas appliances should only ever be installed and maintained by Gas-Safe qualified engineers. Which? Trusted trader Gregor Heating told us about one disaster waiting to happen:

‘We arrived to service a gas boiler, only to find that the homeowner (not a Gas Safe engineer) had given the installation a go themselves. As a result, the boiler was attached with a radiator bracket that could have come away at any time – tearing the gas pipes with it.

‘It had also been installed without a proper flue – the acting flue ended with a simple extension pipe sticking out of the wall, risking exhaust gases not being properly evacuated. Luckily, we were able to safely reinstall the boiler quickly.’

Avoid disaster:

  • NEVER attempt to undertake any gas repairs or installations yourself

  • Always use a Gas Safe registered engineer

  • Which? Trusted Traders has accredited central-heating engineers in your area, who all have the necessary qualifications.

Motor maintenance mayhem

Cars, like many other appliances in the home, involve less mechanical engineering and more IT these days, which makes them all the more difficult to fix without the right equipment. But that doesn’t stop us making mistakes with the areas we can access.

A 2014 Halfords survey found that 10% of motoring disasters were the result of using the wrong motor oil, or not putting antifreeze in the radiator. But the most common error people make with their cars is simply putting the wrong fuel in the engine. This is so widespread that there are companies that specialise in helping out people who are in this situation – just put ‘wrong fuel’ in the search box if you want to find accredited Which? Trusted traders in this field.

Avoid disaster:

Of course, if you have the right tools, materials and know-how, there are jobs you can tackle successfully at home. Read our 10 simple maintenance jobs for you to tackle around the home for some ideas.

Happily, most people have never experienced a DIY disaster – but maybe that’s because more than 70% of people are prepared to pay a professional to take control of home and motor maintenance.  

If you are going to go it alone, don’t take on work that is beyond your skill level. You don’t want to be the next DIY disaster.

More on this…


Here are some other articles you might find helpful