Some of the most commonly attempted electrical and plumbing DIY jobs are the same tasks traders say they're most frequently called in to fix or finish.

To identify the most common DIY problems, in 2023 we asked our Twitter followers to share their worst DIY nightmares. Then we asked 17 of our Trusted Traders for their tricks and tips to help to prevent these disasters before they happen.

If your home needs repairs, visit Which? Trusted Traders to find a reputable trader who has been through our rigorous checks.

The most common DIY nightmares

A total of 54 people responded to our Twitter survey about their worst DIY nightmares. Of those people, 43% said that their worst DIY nightmare was blocked plumbing. Here are the results in full:

  • Blocked plumbing: 43%
  • Sockets and switches: 26%
  • Replacing taps: 22%
  • Light fittings: 9%

Read on for our traders’ home DIY horror stories, and their advice on dealing with them.

Fixing common DIY plumbing issues

Approximately 60% of our Twitter survey respondents reported that their worst DIY nightmare related to their plumbing or replacing their taps.

Our Trusted Traders also reported being called in to deal with this type of issue. One described how issues with DIY plumbing fixes can affect much more than just the bathroom:

‘When I arrived at the client's house, I was greeted by a scene of chaos. The bathroom was flooded, and water had leaked into the hallway, causing damage to the flooring and drywall.’ - Marius Fechete FM Building Ltd

One trick offered by our traders to help prevent DIY plumbing problems was to prepare to deal with any mess before it is made: 

‘Be sure to isolate the water supply, have a small container and a towel handy to catch water from the old tap as you remove it.’ - Flush Plumbing and Heating Ltd.

Another important tip from the same trader related to flexi pipes; it is important not to tighten them too much: 

‘If your tap has flexi pipes you should only put these into the tap hand tight - over tightening with a spanner can snap the threads.’ - Flush Plumbing and Heating Ltd.

If you're not sure how to tackle a plumbing job and want to call in a professional, find a plumber in your area with Which? Trusted Traders.


Fixing common DIY problems with sockets, switches and light fittings 

DIY attempts result in nearly 50% of all severe electric shocks in the home, according to research by Electrical Safety First. The main errors include cutting through power leads, drilling into wiring and repairing electrical items while they’re still switched on.

In our survey, 26% of people reported that their worst DIY nightmare was related to sockets and switches and another 9% to light fittings. 

We also asked our traders about the most common electrical DIY mistakes they saw: 

‘When people add the switch line to a neutral or live terminal, and then the whole thing goes bang!’- Fairfield Electrical 1971 Ltd

‘One of the most common mistakes we come across is customers trying to fit new lights, but [they] do not understand the 3 plate wiring system. [They] join all the reds/browns together and the blacks/blues together and don't understand why the breaker keeps tripping and they then call an electrician to sort the problem.’ - Andy Wallis Redwood Electrical Services

When we asked our traders for advice on preventing this type of issue, the most common suggestion was marking or recording the placement of the wires to ensure everything can be reconnected properly: 

‘If you are replacing a socket or switch, take photos of what cables are going where, and remember that not all sockets and switches have the same live and neutral conductors in the same place, so get a photo of that.’ - Fairfield Electrical 1971 Ltd 

 ‘Use a Sharpie pen to mark the cables so you know where they went.’ - Andy Wallis Redwood Electrical Services

Another trader suggested unplugging the lighting system to help identify the cause of the issue before beginning any fixes:  

‘Intermittent faults on your lighting system? Separate the plugged-in stuff from the hardwiring. Unplug everything. If the fault continues to happen, you now know what the problem is and you can segregate the supply.’ - CSN Services

Visit our guide to hiring an electrician to ensure you know what to look out for and find a reputable electrician near you using Which? Trusted Traders.


Other helpful DIY tips

Some of our traders shared extra tips that were not directly related to the DIY nightmares listed above: 

‘If your nails keep bending when you try and hammer them in, it's because the hammer head is slippery. Rub the hammer head with some sand paper and there will be no more bent nails.’ – Trusted Trader in carpentry

‘If the nails you hammer in keep splitting the wood, blunt the point on a hard surface before hammering them in.’ – Trusted Trader in carpentry

‘Add […] paint conditioner to acrylic (water based) eggshell, satinwood or gloss for smoother flowing application.’ -  Gill Murphy Decor and Cabinetry

‘Always check your subfloor (concrete, floorboards) is level before fitting the floor, this is so that in future the flooring doesn’t fail with telegraphing or the flooring headers and joints breaking.’ - Sheffield Flooring Solutions