Supporting cables in exit routes

[John D v2.0]

Interesting old video, goes beyond the black and white of the regs into an interesting discussion on the grey area of professional judgement

 

[JohnW2]

Interesting old video, goes beyond the black and white of the regs into an interesting discussion on the grey area of professional judgement

I have not yet looked at the video but, in relation to the title of this thread, it's only a few weeks before the scope of this issue will (probably) be far wider than just 'exit routes'.

Kind Regards, John

 

[ericmark]

Interesting, first time I have seen exactly what went wrong, three major points made, one is there were regulations covering fire alarm before amendment 3 so non metal retention of fire alarm cables is non compliant.

Second is plastic raw plugs are no good.

And the third point even if not forced by regulations, now we know the dangers these should be reported.

I think the major point is plastic raw plug, if you need metal raw plugs then some re-design is required, likely either metal trunking or tray work to hold all cables, however we are also told extra low voltage and low voltage should not be mixed. It may be time to rethink the risks of running services together.

 

[mattylad]

Hmm, I find this is giving me a kick up the bum and reminding me of a pack of rawlbolts I have at work and why I got them (for this very reason).
The metal trunking that passes over a fire door is fitted poorly and with some plastic plugs, so the next time I'm doing the factory rewire Ill ensure that changing these is done.

 

[ban-all-sheds]

Did the DPC introduce a definition of "premature"?

 

[JohnW2]

I see no definition of "premature" or "premature collapse" in the DPC - only a requirement that wiring systems be supported it such a way that it will not be liable to it ("premature collapse") in the case of fire!

 

[ban-all-sheds]

And there we have it.

If the term is undefined then who can possibly say that a cable support system has, or has not, collapsed prematurely?

 

[JohnW2]

As with 'non-combustible' CU, there are 'notes' to the regulation (in DPC) which give an example of what would be deemed to satisfy this regulation - and, in this case, also examples of things which would not satisfy the regulation ....

NOTE 2: This regulation precludes, for example, the use of non-metallic cable clips or cable ties as the sole means of support
where cables are clipped direct to exposed surfaces or suspended under cable tray, and the use of non-metallic cable
trunking as the sole means of support of the cables therein.
NOTE 3: Suitably spaced steel or copper clips, saddles or ties are examples that will meet the requirements of this regulation.

 

[ban-all-sheds]

Says nothing about non-metallic fixings.

 

[mattylad]

Does it really have to?
After watching that video it seems that its common sense to use all metal fittings and ensure that no wires can fall down.

Do you really need a regulation to tell you to do that?

 

[bernardgreen]

Do you really need a regulation to tell you to do that?

Some installers, often masquarading as "engineers" really do need regulations to tell them how to install things. Sad state of affairs but too often the reality

 

[ban-all-sheds]

Does it really have to?

Yes.

After watching that video it seems that its common sense to use all metal fittings and ensure that no wires can fall down.

This is not an observation limited to or relating to this issue - it is one which applies to the entire generic system of any laws or regulations governing any behaviour or activities:

Try having a situation where people are prosecuted for doing something when there is no explicit law or regulation forbidding it and telling them "it seems that it's common sense that what you did should not be allowed".

Do you really need a regulation to tell you to do that?

Since they chose not to impose a specification for how long the support systems should withstand a fire, yes.

 

[FrodoOne]

It was interesting that the video showed
a test with metal screws into plastic plugs - which melted,
metal screws into concrete - which held
BUT
it did not show tests for metal screws into "fibre" plugs (a substitute for wooden plugs), which might to have been eventually expected to "char" but may have lasted much longer than the plastic plugs.

 

[JohnW2]

... it did not show tests for metal screws into "fibre" plugs (a substitute for wooden plugs), which might to have been eventually expected to "char" but may have lasted much longer than the plastic plugs.

I don't know what the situation is in Australiabut, over here, the fibre plugs (which was previously more-or-less what they all were, after asbestos-based fixings disappeared) largely vanished in the UK two or three decades ago, replaced by plastic ones.

Kind Regards, John

 

[FrodoOne]

I don't know what the situation is in Australiabut, over here, the fibre plugs (which was previously more-or-less what they all were, after asbestos-based fixings disappeared) largely vanished in the UK two or three decades ago, replaced by plastic ones.

Kind Regards, John

John,
You are indeed quick in your response and a quick check shows that "fibre wall plugs" do no bring up any response from local suppliers!

The fact that I can remember them (possibly) shows that I am getting old.

However, the need for something which would not melt in a fire situation might be a good reason for "bringing them back".

The "fibre" plugs that I can remember were not like asbestos but were brown and like sisal/rope etc. - with some type of stiffening agent.