Expert warns against making these 10 dangerous electrical DIY mistakes

Expert warns against making these 10 dangerous electrical DIY mistakes

6th July 2022

Expert warns against making these 10 dangerous electrical DIY mistakes

Interest in DIY has rocketed over recent years, but there are some jobs which should always be left to a professional, and many of these are electrical in nature.

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The risk of injury, fire and property damage is always present when working with electricity, but certain mistakes carry a particularly high element of danger.

That’s why we’ve consulted with hundreds of UK electricians to reveal the 10 most dangerous mistakes people can make, and asked John McCallister, electrical expert at, to explain why they are so hazardous.

Electrical Fire

 1. Leaving plastic-sheathed cable unprotected

“Leaving cables like these unprotected exposes them to snagging and cuts. Running them through a conduit prevents this, minimising the risk of fire and lethal shocks.”


2. Leaving sockets and switches loosely connected 

“Loose connections cause movement that has the potential to disrupt the power supply or allow live wires to wiggle loose, exposing them to your fingers. So, there’s a potential risk of electrocution or fire.”


3. Cutting wires too short 

“Cutting wires too short makes connections difficult to complete safely and increases the risk of electrocution and shorting.”


4. Recessing boxes behind the wall surface 

“This mistake increases the likelihood of fire, both from the heat and from the sparks potentially coming into contact with combustible materials.”


5. Installing cable without a clamp 

“Cables that are left loose at entry points are going to move and strain, causing damage and potentially exposing the wires. This damage can lead to overheating and electric shocks if bare wires are touched.”


6. Connecting wires outside of electrical boxes 

“Electrical boxes protect connections from damage and pulling loose, as well as preventing exposed wires from accidentally coming into contact with other wires. Such boxes prevent sparking, shorting and overheating, so connecting wires outside of them could easily lead to a house fire.”


7. Overfilling electrical boxes 

“A junction box that’s crammed full of wires because it’s the wrong size or wired incorrectly is likely to overheat or short, causing a fire.”


8. Reversing live and neutral wires 

“If live and neutral wires are mixed up, then this could prevent circuit breakers from being able to shut the electricity supply off. This makes circuits and appliances potentially lethal.”


9. Wiring a circuit breaking device backwards 

“Mixing up the line and load on a circuit breaking device, such as an RCBO or MCB in the UK or a GFCI in the US, risks your electricals operating with no safety cut-off in the event of a fault. This leaves you open to fires and potentially lethal shocks. Thankfully it’s a very rare problem in UK electrical installations as they should be completed and certified by a qualified and competent engineer.”


10. Installing electrical outlets close to water 

“As water is a great conductor, electricity can travel through it. That’s why sockets and switches should be at least 30cm from water sources, such as sinks, to prevent electricity passing through you to the ground.”


If you’re an electrician who has been hired in relation to any of these jobs, check out our range of supplies, from sockets and switches, to consumer units and cables.