Chasing cable in a ceiling

[Gigsy]

I permitted routes are only in walls.
Internal corners, near the ceiling and horizontally and vertically from accessories.
Laying cables above ceilings is fine, but there are no permitted routes.
Usually it is only where cables run through joists or battens that extra precautions are required.
In the gaps between the joists, cables aren't held in place, so screws or nails will just push them aside.
Where cables are held in place as the pass through joists, the cables have to be 50mm deep, have mechanical protection or have an earthed sheath.
If you have plastered the whole cable, you only real option is to change the cable for one with an earth d sheath, because the cable is held in place the whole length.

I know BS7671 provides recommended permitted routes in walls. BS7671 are guidelines which if you follow help you comply with the building regulations and therefore the law. I can not see anywhere in the wireing regs that forbid me to chase a ceiling and run a cable in the ceiling. I do not think this is dangerous if protected by an RCD. The regs state rules for running cable in walls and in the gap between the ceiling and floor boards. It does not forbid, let alone mention chasing ceilings. If it is not forbidden in the regs, or not even mentioned in the regs, is it then illegal to do? I have installed a cable in a ceiling. I chased the ceiling ran a cable under plastic capping, then plastered the ceiling.

 

[Darkwood]

The regs say 50mm below the surface, why do you think this only applies to walls only?

 

[Leesparkykent]

Cables need to be at least 50mm from the top or bottom of the joist/baton it passes through. If its not 50mm from the top or bottom there needs to be something sufficient enough to stop the penetration of nails, screws and the likes of. This method is normally harder to achieve so using a cable which has an earthed metallic covering is an easier alternative.

Other methods are available but in your situation are not practical to use such as be installed in earth conduit, enclosed in earthed trunking/ducting or forms part of a SELV or PELV circuit.

If these methods are used the earthed metallic covering of the cable, earthed conduit, earthed trunking/ducting needs to comply with the requirements of a circuit protective conductor.

You have installed a cable that is not 50mm from the top or bottom of the joist, doesn't have sufficient protection to stop the penetration of nails/screws, doesn't have an earthed metallic covering, is not installed in an earthed conduit or earthed piece of trunking/ducting or part of a SELV/PELV circuit.

The work you have done does not comply with bs7671 which is a minimum standard to which we work. Your work doesn't go above and beyond the requirements of bs7671 either so does not comply. As it doesn't comply it consequently doesn't comply with the building regs.

You've come here seeking advice because your worried that the work you've done doesn't comply well it doesn't.

 

[Pat H]

Dig the plaster away at each joist point.
Add a recessed metal plate for protection. (normally used on top of joists but will work under them)
Re plaster. Ensure circuit is RCD protected.

 

[Wilko]

Dig the plaster away at each joist point.
Add a recessed metal plate for protection. (normally used on top of joists but will work under them)
Re plaster. Ensure circuit is RCD protected.

Hi - sorry to say Pat, but this doesn't solve it I think. The cable trapped in the ceiling plaster remains hidden and not in any safe zone and fixed closer than 50mm from the surface.

 

[Deleted member 26818]

At the end of the day, it's your flat.
If you want to do something which doesn't comply that's your choice.
It will only become a problem if you forget where the cable is run and bang a nail into or screw something into the cable. Or if you sell the place, rent it out and the new owner or tenant does it.

There's no requirement for you to notify this work, so Building Control will not know about it and will not issue an improvement notice.

Whilst RCD protection may make things safer, it is not a acceptable method for complying with the Regulations.

So your options are:
Re-run the cable on the surface of the ceiling,
Re-run the cable using a cable with an earthed metallic sheath,
Re-run the cable, chasing it into the ceiling to a depth greater than 50mm,
Provide mechanical protection for the part of the cable that is plastered over,
Re-run the cable in earthed conduit and plaster the conduit into the ceiling,
Hope that nothing goes wrong.

 

[Pat H]

Assuming of course that the joist notches are within the specified range on the joist.

 

[Pat H]

How can the cable be plastered in the ceiling thickness? I assumed its loose between joists.
That's what I would have done. cut a circular hole each side of each joist. Chase across the joist and into the joist.
Metal plate over the joist notch. Cable free to move. Cable free to move between joists.
That way, if need be, a replacement cable can be pulled through the whole length if it gets damaged etc.
Then plaster the holes and over the metal plates ensuring the cable isn't glued by the plaster.

 

[Deleted member 26818]

Yes, does seem weird.
Saw post #8, which is why I asked the question in post #9.

 

[Pat H]

If you chase right through a plasterboard ceiling you end up with two flaps that will move around even after a plaster patch.

 

[Wilko]

Hi - according to OP post #8
"Technically what I have done is not under a ceiling it is actually in the ceiling. The cable is plastered over, it technically forms a part of the ceiling" .
Must be a thick plaster ceiling?

 

[Pat H]

Hi - according to OP post #8
"Technically what I have done is not under a ceiling it is actually in the ceiling. The cable is plastered over, it technically forms a part of the ceiling" .
Must be a thick plaster ceiling?

As long as its more then 50mm thick and the cables at the top. then all's fine ;-)

 

[westward10]

I would have liked to have seen some before and after pics.

 

[Leesparkykent]

You aren't supposed to notch the bottom of joists.

 

[westward10]

You aren't supposed to notch the bottom of joists.

Not sure he has, I think he has just cut a channel across the plasterboard.