Fire rated clips - any suggestions?

[mydigitalhome]

Yes, I would agree where a typical plasterboard ceiling is installed, not required. False tiled suspended ceilings or above stretch ceilings or any cable that is directly fitted to the ceiling would require metal restraints.

I think it is fair to say that if another building element has to come down before the wiring, then the wiring hasnt collapsed prematurely.

sums it up nicely.

 

[netblindpaul]

The duration of standard plasterboard varies dependant on source although I could be persuaded that the regulation does not include cables within the fabric of the building.
The plastic plug fixing is where I disagree and would be interested in your sources for such info.. The BRE have done extensive testing and published their conclusion which is the advice the IET and many other bodies tend to follow, their conclusion for plastic plugs is they are not suitable so I find it strange that this advice will be ignored when it is safety critical.
https://electrical.------.org/media/1578/fire-performance-of-cable-supports.pdf

My sources are from JPEL64, JPEL64 panels, the WRPC, & the IET, the NICEIC, STROMA & NAPIT.
That report has been discussed by the above, as have the results, and BRE have been involved, and the consensus is that cables above a plasterboard ceiling do not require any additional support, as the plasterboard is deemed from Building Regulations to be a 30 minute fire barrier, unless it is incorrectly installed, but, they cannot allow for that, because it opens up a whole new can of worms.
The situation with plastic plugs has also been discussed between those above, and BRE, and it has been deemed that they will comply.
I have been told that there will be a statement on this shortly, it should have been out at the end of last year, but it has not surfaced yet, I don't know why.

 

[Darkwood]

Fair enough NetBP ... but I fail to see how they can accept plastic plugs as a means of fixing when they have been shown to fail repeatedly under test conditions, I agree and can see the argument with cabling within the structure but fail to see how they can ignore the results of the BRE on this matter given the BRE themselves conclude they are not sufficient, I will be interested in the exact wording of these bodies and if they do indeed fully accept the use to the plastic plugs with regards to the topic in discussion.

 

[Malcolm Broomfield]

Q. Do contractors still have to use metal/fire resistant clips above fire proof plasterboard ceilings?

A.

1. firstly let's look at new build, houses etc, all new builds have the cables run through the joists and or clipped to the joists before the plasterboard ceiling is erected so fully compliant if metal clips used.
2. plasterboard gives up to 30 minutes protection from heat it is not Fire Proof.
3. if you go to Siniat fireboard for example for the walls and install it correctly this gives up to 60 minutes of protection and weighs 31 Kg per sheet it is not fireproof.
4. GTEC fire board square edge again can give you some protection but the manufacturer states; Fire resistance is determined from the ‘system’ being constructed. For example; a partition, lining or ceiling. When assessing fire resistance the supporting framework needs to be considered, as well as insulation, fixings and tracks etc. Plasterboard cannot be deemed to be rated by itself in all scenarios, regardless of application. all of the above Achieve Part B Building Regulations (Fire)

for openness and transparency, I became an electrician in 1973 and a chartered safety practitioner nearly 15 years ago. In June 2000 I was in a flat following a fire in which I suggested a clip that would fit into trunking to save lives that is now on sale with many more under the firefly cable clips brand. this is not a sales pitch and I will never put any links on here but with the level of experience and qualifications I have within electrical and safety, I would like to post updates to questions answered as above. If admin deems this to not be allowed then I will back off and just answer directly to the questioner?

 

[mattg4321]

Hi Malcolm. Your answer runs to many sentences but doesn't appear to actually give an answer!

With respect, it does seem your opinion will be biased, as you have very honestly admitted to not being impartial.

 

[Malcolm Broomfield]

I am biased, I worked for Southampton City Council as an electrician for 12 years and worked in all of the tower blocks including Shirley Towers where 4 firefighters died. the above is from a longer answer given elsewhere and the info within comes from the plasterboard manufacturers.
My son in law is a firefighter and I have been involved with safety and especially fire for a very long time.
If the brigade has a ground floor fire and use hoses from above this will bring the plasterboard ceiling down and any firefighters passing through could be trapped by the falling cables. we have to look at this from all angles and one is how the fire brigade fight fires. Another area to consider is that at ceiling height we could have 800 degrees c and at ground level a few degrees above 100 with firefighters in breathing apparatus sweeping for injured persons.

I became an electrician after a five year apprenticeship starting in 1973 under the 14th edition of the regulations and have sat each of the upgrades since up to the 17th edition, this week I sat in on one of the one day courses for the 18th upgrade and this question was asked there and it was answered "of course the cables should be fixed "do you want to be responsible for injuring another fire fighter because of laziness"?

 

[Malcolm Broomfield]

Sorry for all of the posts but I feel it is important that we use metal fixing everywhere and that is my personal and professional answer to any electricians that ask.
Plastic plugs deform at a very low temperature so by the time we get to a few hundred degrees c anything supported is starting to pull against the screw and the plug. we all know there are plenty of "concrete screws" we can use without plugs so again its simple changes that will inevitably save lives. Most wholesalers and SWA now have metal cleats and clips available for all sizes of cables so let's try them and see how we get on?

 

[mattg4321]

Interesting, and I agree in principle.

But, the regulations don't seem to support your view, or at best they are very vague. There is no guidance as to what would be a premature collapse. As Davesparks said above, most cables in ceiling voids will run through joists at regular intervals and will thus not sag if the ceiling collapsed. However those that run parallel to the joists may.

The biggest problem for most people is that unless this is vigorously enforced/checked you will be competing against many people who won't be using these methods above ceilings. What do we reckon the chances of the big house builders going down this road are!?

I also wonder how this would affect rewires. I wouldn't fancy pulling flooring up everywhere just to bang a clip in.

I know there are some available already, but they don't look convincing to me, but maybe a commercially viable way round this would be a well designed/manufactured staple for the likes of twin and earth. Shouldn't cost any time (will probably save) and shouldn't be too expensive once you have a stapler.

 

[Strima]

And here lies the problem, we need guidance as to what sort of support is needed above a plasterboard ceiling.

What is defined as premature collapse?

As has been pointed out above, what about rewires, are we to now fully lift floors above to clip cables in rather than fishing them through?

 

[Malcolm Broomfield]

thanks for these answers they are really enlightening and hopefully the replies will help or at least spur conversations. A couple of points, no regulations can be enacted retrospectively so if you are adding a socket etc to a circuit which has already been installed you do not need to fix every other cable in the house with clips. secondly, a premature collapse is where the surface drops, prior to demolition (before the end of its life). where you are pulling through a T+E it would be expected that if you used clips at each end to support the cable and could not raise the floor easily then this would be acceptable if pulled tight. This has to be what safety professionals call "reasonably practicable" As a safety consultant I wanted the use of clips added to the NICEIC test and inspect sheets to confirm it has been completed, no mention of proving this anywhere. If anyone is interested I will do a short post on how the clips are tested etc this actually explains a lot about conditions in a fire.

 

[sparksfly]

IDEAS
Used an old bucket of large 5" steel nails....
Bang nails in floor/ceiling joists lay cables on top, secured by the odd steel cable tie or recycle wire twisted around cable/nail...job done.
I have also been using black banding on exposed black beams in escape routes & inside plastic trunking.
Sprayed metal conduit saddles white/black for pvc conduit support.
Do we really need some bigwig seal of approval or shall we just get on and do it with some common sense and creativeness.

I do like some of the informative comments written previously and interested on how clips are tested but no more tick boxes on test/inspect sheets please...the more ticks you have the less is read.

To Strima & mattg..I agree, usual appalling lack of guidance/thought on some practical issues in regs...Part lifting flooring in a room? could we not use catenary/steel wire for support ?
1) Steel cable tie T/E cables together, some loose fixed position tie loops.
2) Steel wire threaded through loose loops
3) Pull the lot under floor
4) Nails in joist both ends, steel wire fixed both ends taking the strain, even if there was a slight drop if the ceiling failed cables would not be falling into necks of persons (unless very low ceiling or span too long)

 

[Dave OCD]

Has any testing been carried out using 'normal' clips with the fixing nail always on the bottom/underside of the secured cable ? I just wonder if the clip pins alone would continue to support if the plastic part melted ?

 

[Malcolm Broomfield]

Catenary a great idea, fish through with the cable brilliant. Testing of clips, generally the testing is done with the cable it needs to support we used FP100 or 200 Gold but requested the heat was directly on the clips. this is at 930degrees + or - 40 so up to 970 degrees for two hours. The cables are also hit with basically a hammer and sprayed with water occasionally throughout this period. this replicates the heat, the fire brigade hoses and water and falling debris. The clips have to remain in place supporting the cables throughout. so the likelihood of the pin still supporting the cables as mentioned earlier is low to zero.

 

[Octopus]

This reg change is nearly as daft and ill thought out as the metal clad fuseboards ..

What is the guidance for cabling on sheds ..... Metal clips that last longer than the wooden structure they are attached too...

 

[Bellendian]

To be honest I think the reg is a half reasonable attempt to solve the relatively simple issue of dealing with surface mounted wiring, which could possibly have been secured with nothing more than the double sided tape on the back of the trunking, prior to this.
On the other hand I take issue with a number of Malcolms points.
His definition of premature collapse as being any failure prior to intentional destruction by way of demolition is clearly absurd.
He also states that use of water to extinguish a fire on upper floors may give rise to the plasterboard ceilling below falling through, therefore allowing wiring to collapse. I am unsure of his argument here. If the plasterboard had survived the fire prior to impact of firefighting water, or was never exposed to fire, then the use of metal clips is irrelevant, and plastic clips would be just as effective in supporting the wiring in this situation.
As for statements that plasterboard isn't fire proof, just fire resistant, but we should use metal fire proof clips...I ask this. Why is it that steel structural members require protection from fire, and why is it that this protection is often delivered by means of plasterboard cladding?