Cabling zones exist to reduce the risk that you could accidentally cut or screw into an electrical cable when doing day to day jobs such as DIY or hanging pictures.
The cable zones exist as areas where concealed cables should be run so these are the areas to be avoided when drilling into walls.
Electrical cables should not be found outside of these zones however in many older (and some newer) properties they often are so this is something to be cautious of when chasing or chopping sections out of a wall.
For many reasons it’s useful to know where the safety zones are. If you are doing some of the first fix yourself by chasing out the walls you must ensure you keep to these zones. It’s also handy to know where the zones are if you are planning on drilling into a wall. Avoiding these zones will reduce your chances of accident or injury.
So which areas are the zones where the cables are run?
- Top of the wall – where the wall meets the ceiling there is a 150mm zone where cables should be run. This is at the top of the wall and runs horizontally around the whole room.
- Join between two walls – where the two wall meet there is a safety zone on each wall from the join. This is for any joins in a room and will always run vertically down from the corner.
- Horizontally and vertically from any switch or socket – the zone runs horizontally from both sides of the socket until it reaches a corner or an obstacle such as a door, and vertically the width of the socket or switch up to the ceiling and down to the floor.
- If a partition wall is less than 100mm thick then the cable safe zone for a socket or switch will run on both sides of the wall.
In the event that a cable cannot be run in these zones cables the cable must comply with one of the following –
- Be over 50mm below the surface, if the wall is made from metal, then it will need RCD protection
- The cable should be armoured with an earthed armour or metal sheath
- The cable should be in metal trunking or conduit which is earthed
- It should have protection from at least 3mm steel.
Generally, it’s much easier to run cables under the floor however this isn’t possible with a concrete floor which is why the safety zones are used to run the cables down to switches and sockets.
Cables can be run under wooden floors however there are some restrictions and there are rules about where you can notch and drill through a joist as any holes can weaken the joint. The cable must also be at least 50mm from the edges of the joist, effectively 50mm from the ceiling below or floor above.
Awareness of the safety cabling zones is in everyone’s best interest, especially to be considered when doing DIY involving drilling anything into a wall to avoid any accidents coming into contact with an electrical cable.