Warehouse wiring

[mibh76]

I'm converting a warehouse that was an exhibition space into a trampoline park.

Need to:

• Replace twenty flouro tube lights with LED equivalents
• Move six plug sockets 6 inches to the left (currently surface mounted with cabling encased in trunking)

Contractor says we need to rip out wiring and start from scratch because:

• Current wire is a grey twin and earth that causes excess smoke and is only suitable for domestic.
• Current wiring is attached to redundant old pipework and ceiling trusses (4mtrs off the ground) by cable ties.
• Some back office wiring is surface mounted and not running inside trunking.

He says “even if our electricians test everything and it is ok, if it doesn't meet regs Building Control may not accept it due to the extent of install you are carrying out they may request everything is replaced"

Sound like it is necessary or could the existing wiring remain? Site was certified safe with Napit Electrical Installation report in 2018

Ta

 

[littlespark]

If anything is open to the public, I would suggest you make it as safe as possible.

In reality, a complete strip out and redo may work out cheaper than having cables running to sockets you now can’t access due to your equipment, and having to ensure safety there.

The back office may just need cleaning up.

if you ask electricians to price the job, ensure you state you require LSF (low smoke and fumes) cables to satisfy the building regs.

 

[Dustydazzler]

i Would be tempted to strip everything out and start from scratch.
I dint like pvc pvc twin and earth in commercial settings.

 

[MJPD29]

Cables cable tied to pipes is less than Ideal, suitable containment would be preferable. I wouldn't personally use twin and earth in a commercial setting either. There will always be someone in the general public who is looking for a fault or an excuse to claim, so making it as safe as possible is advisable. If all the cables in the sockets are too short then rewiring would be my preferable method rather than 6 junctions in the cable

 

[mibh76]

If anything is open to the public, I would suggest you make it as safe as possible.

In reality, a complete strip out and redo may work out cheaper than having cables running to sockets you now can’t access due to your equipment, and having to ensure safety there.

The back office may just need cleaning up.

if you ask electricians to price the job, ensure you state you require LSF (low smoke and fumes) cables to satisfy the building regs.

Thanks for the post. The sockets will not be behind any equipment and are all in trunking so meet current regs. I'll
I was under the impression they have to use LSF without me specifying it as they would be in breach of regs and therefore wouldn't be able to use anything else?

 

[mibh76]

i Would be tempted to strip everything out and start from scratch.
I dint like pvc pvc twin and earth in commercial settings.

Thanks for the reply. Is PVC twin and earth in commercial settings against building regs? I'm really looking for tangible reasons to remove it doing so would cost £20k more which I'd prefer not to spend other than if strictly necessary...

 

[James]

I do not believe that pvc cable, twin and earth or otherwise is a problem in most commercial buildings.
some places may require it, such as high rise buildings, underground etc.

nearly every factory unit i visit is covered in it.

have you had a fire risk assessment done?

 

[mibh76]

Cables cable tied to pipes is less than Ideal, suitable containment would be preferable. I wouldn't personally use twin and earth in a commercial setting either. There will always be someone in the general public who is looking for a fault or an excuse to claim, so making it as safe as possible is advisable. If all the cables in the sockets are too short then rewiring would be my preferable method rather than 6 junctions in the cable

Hey, thanks, really appreciate this info. I understand containment would be preferable but is that because cable ties are against the regs? The cables are that are held with the ties are 4mtrs off the ground so out of harms way, they'd need to climb up a ladder to reach them...
Not sure I understand what you mean about the 6 junctions thing? I meant each plugs sockets need to be moved a few inches to the left of their current location, the wiring doesn't need changing.. Cheers

 

[James]

Hey, thanks, really appreciate this info. I understand containment would be preferable but is that because cable ties are against the regs? The cables are that are held with the ties are 4mtrs off the ground so out of harms way, they'd need to climb up a ladder to reach them...
Not sure I understand what you mean about the 6 junctions thing? I meant each plugs sockets need to be moved a few inches to the left of their current location, the wiring doesn't need changing.. Cheers

the regulation they will be looking at here is the requirement to prevent premature collapse of wiring systems in the event of a fire.

basically plastic cable ties are not going to hold cables up when they get hot.
ideally, cables would be run in trunking or cable tray and if cable ties are required they should be fire resistant (metal)

 

[mibh76]

I do not believe that pvc cable, twin and earth or otherwise is a problem in most commercial buildings.
some places may require it, such as high rise buildings, underground etc.

nearly every factory unit i visit is covered in it.

have you had a fire risk assessment done?

Hi, thanks for the reply, this has been stressing me for some days so good to get some help with it.
The main contractor (who is subcontracting the electrical work out) will be doing the Fire Risk Assessment as soon as we sign the contracts and pay deposit to start work. He's happy though there are plenty of fire escapes (3 in the 10k sq ft warehouse). We also have an independent fire alarm specialist fitting the alarm and he was happy with the fire escape situation too.
Will the fire risk assessment impact whether we have to rewire the old cable tied grey flex? Cheers

 

[mibh76]

the regulation they will be looking at here is the requirement to prevent premature collapse of wiring systems in the event of a fire.

basically plastic cable ties are not going to hold cables up when they get hot.
ideally, cables would be run in trunking or cable tray and if cable ties are required they should be fire resistant (metal)

Thanks. Does that mean that the flex that is currently attached with cable ties will need to be removed or retrofitted with fire resistant cable ties?
I was under the impression that as long as something was done within regulations when it was installed it was ok as long as nobody tampered with it (though replacing light fittings is ok..)
Also, if you don't mid me asking, do Building control often just walk into a building and tell you to rip it all out or do they complete a report that illustrates where the problems are that need to be repaired? Thanks again forth help.

 

[MJPD29]

Hey, thanks, really appreciate this info. I understand containment would be preferable but is that because cable ties are against the regs? The cables are that are held with the ties are 4mtrs off the ground so out of harms way, they'd need to climb up a ladder to reach them...
Not sure I understand what you mean about the 6 junctions thing? I meant each plugs sockets need to be moved a few inches to the left of their current location, the wiring doesn't need changing.. Cheers

The 4m thing is irrelevant, I wouldn't accept them cable ties to pipes at all. They do not prevent the cable from premature collapse in the event of a fire and if it is a hot pipe it will weaken the cable ties over time.

 

[mibh76]

The 4m thing is irrelevant, I wouldn't accept them cable ties to pipes at all. They do not prevent the cable from premature collapse in the event of a fire and if it is a hot pipe it will weaken the cable ties over time.

Hi again, thanks for your thoughts.
The height of the wiring is relevant as it corresponds to the likelihood of people being to tamper or knock the cables and damage them / themselves. If no one can reach them then there is a negligible chance anyone can hurt themselves.
The cable ties were installed before the 18th edition changes that stipulated that new work must use metal fasteners and therefore doesn't need to be changed and the pipes aren't going to be hot has they're redundant (redundant means not in use).

I'm really looking for tangible reasons that the work will need to be replaced rather than anecdotal reasons but thanks all the same.

 

[DPG]

Hi again, thanks for your thoughts.
The height of the wiring is relevant as it corresponds to the likelihood of people being to tamper or knock the cables and damage them / themselves. If no one can reach them then there is a negligible chance anyone can hurt themselves.
The cable ties were installed before the 18th edition changes that stipulated that new work must use metal fasteners and therefore doesn't need to be changed and the pipes aren't going to be hot has they're redundant (redundant means not in use).

I'm really looking for tangible reasons that the work will need to be replaced rather than anecdotal reasons but thanks all the same.

The metal cable fixing regulation is to prevent people and possibly firefighters getting tangled up in wires that may drop down in the case if a fire if only plastic ties are used.

I suggest you stop looking for a way to get around this. The judge will take a dim view of you trying to save money if something goes badly wrong in the future.

 

[MJPD29]

Hi again, thanks for your thoughts.
The height of the wiring is relevant as it corresponds to the likelihood of people being to tamper or knock the cables and damage them / themselves. If no one can reach them then there is a negligible chance anyone can hurt themselves.
The cable ties were installed before the 18th edition changes that stipulated that new work must use metal fasteners and therefore doesn't need to be changed and the pipes aren't going to be hot has they're redundant (redundant means not in use).

I'm really looking for tangible reasons that the work will need to be replaced rather than anecdotal reasons but thanks all the same.

Cable ties on a pipe would never have been acceptable. Not on the 17th, 16th or any other. It could be worth getting a second opinion on site from another spark to see if it really needs done. To me, you are trying to cut corners and make excuses not to make your installation safer to save yourself a few quid. Remember it is the public you are dealing with, and should anything happen you will get hammered for it. It sounds like a rough job, and probably does need re-done. If you really don't want to get the work done im sure you'll find someone out there that will sign a bit of paper for 50 quid that says its all ok, but that's on your head.

 

[MJPD29]

And as for the cables being 4m in the air, they aren't fixed properly,so whether that is 1000m in the air on 1m in the ait its irrelevant, it is and always will be unacceptable

 

[littlespark]

Its going to be a trampoline park... is 4m really going to be out of reach?

 

[mibh76]

The metal cable fixing regulation is to prevent people and possibly firefighters getting tangled up in wires that may drop down in the case if a fire if only plastic ties are used.

I suggest you stop looking for a way to get around this. The judge will take a dim view of you trying to save money if something goes badly wrong in the future.

Hi DPG, thanks for the input. Certainly not looking for a way around it, just hoping for some clear advice. Looking to understand whether all the old wiring that was up to regs at the time when it was installed needs ripping out or not.
Obviously the price implications between leaving it and keeping it is huge.
Cheers

 

[mibh76]

Cable ties on a pipe would never have been acceptable. Not on the 17th, 16th or any other. It could be worth getting a second opinion on site from another spark to see if it really needs done. To me, you are trying to cut corners and make excuses not to make your installation safer to save yourself a few quid. Remember it is the public you are dealing with, and should anything happen you will get hammered for it. It sounds like a rough job, and probably does need re-done. If you really don't want to get the work done im sure you'll find someone out there that will sign a bit of paper for 50 quid that says its all ok, but that's on your head.

Hi, thanks again and appreciate the advice but would be good if we could not cast aspersions about a persons character, especially coming from a Chelsea fan

Ha, but no, in all seriousness, i'm certainly not looking to cut corners, very happy to pay where necessary but you are incorrect about the cable ties, they've been a perfectly acceptable and widely used form of mechanical fixing up until the most recent regs change, plenty of literature out there about that fact.

I'm hoping to understand whether it is necessary to rip them out (at a cost of 20k) because I want to change the Flouro tubes to LED's... Don't forget, site was Napit certified as safe in 2018..

Ta

 

[mibh76]

Its going to be a trampoline park... is 4m really going to be out of reach?

Thanks, yep, the tramps are out of the way of the trusses, in a diff area.

Cheers