Fire Supports on Cat5 cables EICR

Well BS7671 is concerned with premature collapse. So as long as cables don't start falling before the suspended ceiling itself starts failing, then its not really an issue. The usual concern with such ceilings is when someone has to poke their head above them and they encounter a mass of chocblock connectors, unsheathed LV cable ends etc.

I agree - if the ceiling grid itself is of the usual all steel construction held up with steel wires and steel fixings into the concrete, I would have thought it would have provided quite adequate support for a few data cables even during a fire. If there were a huge number of cables such that their weight might greatly exceed what the grid could carry (either in normal conditions or perhaps if weakened by heat from a fire), that might be an issue - but that would perhaps be less usual.


  - Andy.

Regardless of PoE, the installation of ICT cables has to comply with BS 7671, even if they are just data, and even if they are fibre. BS 6701 says so as well as BS 7671.

The ceiling grid isn't part of the building structure, and isn't British Standard rated as a cable support, so I wouldn't accept it as a compliant wiring support system.

Apart from anything else, chucking cables over ceiling grid is just plain lazy workmanship, especially when there's an existing support system that could easily have been used with a few metal cable ties every couple of metres. C3 or not, the client got a poor job.

The ceiling grid isn't part of the building structure, and isn't British Standard rated as a cable support, so I wouldn't accept it as a compliant wiring support system.

What's the BS for a hole through a joist above a plasterboard ceiling?


    - Andy.

Part of the structure, innit.

OK, that wasn't a well chosen example...


My point was that compliance with a BS shouldn't be the only or even the main criteria for deciding whether something is suitable - especially for an EICR where we're meant to be deducing whether the installation is safe for continued use (using thee current version of the regs as a yardstick for the level of safety to be expected). Some things that don't have a BS (I'm now thinking of proprietary systems like unistrut) are likely to perfectly satisfactory in practice and their actual safety or suitability isn't really reduced at all by the lack of a bit of paper certifying compliance with something or other. Likewise just because and item of equipment does comply with a BS it doesn't necessarily mean it's suitable for every particular situation (the debacle with BS 1363 sockets and EV charge points come to mind).


For sure compliance with a BS is a nice easy way of palming off most of the hard thinking onto someone else and of course BS 7671 demands a certain level of compliance for a new installation - but we should not overlook the judgement that should also be applied in every situation.


Most ceiling grids for example are intended to directly supply 4'x2' light fittings - weighing in at several kg each - is it really plausible to suggest a few tens of grams of cat 5 in the same area will make an appreciable difference to the systems support capabilities?


I do agree that slinging cables over a grid isn't exactly good practice - but sometimes there are few alternatives especially when the ceiling is already up and the space underneath a fully populated office. CAT 5 (and higher) really doesn't want to be supported from a catenary wire with a few ty-wraps (data cable installation standards demand protection of the cable's geometry for performance reasons) and getting anything like tray or basket up there is likely to be difficult and disruptive - i.e. expensive - and customers tend to prefer cheaper solutions.


   - Andy.

There are suspended ceilings and suspended ceilings - The sort that wobble and look like they may collapse in a strong wind are probably a hazard in an emergency,  if there are network cables or not, some folks idea of a fixing for a suspension wire seems to be a few screws and a plastic plugs as far apart as possible. Others use fittings that bolt into concrete for considerable depth, and in the best cases anchors have been cast in during building construction of a size that could probably support a small car .


The same is true of baskets and cable trays - I have (gingerly) walked, well shimmied,  my way across some that were holding up some very large SWA, having convinced myself my weight was but a small addition, and they did not even flex.  (I was younger ...) Other places I have looked up and shaken my head in wonder that things  are actually staying up.


So, if there is to be a comment in the report, and perhaps their should be,  it needs to be about the suitability of that particular ceiling, rather than a general statement, or maybe a recommendation that someone better placed to do so inspects and makes a judgement.

As per Andy's point, there may be a BS no. for installing ceilings, but I reckon most installers do not read it very often,or maybe ever, and rather like the example of unistrut, a decision based on how much it moves and what it is attached to is needed.

I don't really see the issue as the IT cable will not be collapsing any more that the ceiling support grid so is adding no additional danger.