EV charge point. Cable may have to run above a doorway.
CU, head and meter enclosures fire resistance
- Thread starter frank999
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EV charge point. Cable may have to run above a doorway.
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Domestic premises do not have official escape routes.
A domestic dwelling configured as an HMO will have 'protected escape routes', with emergency lighting, signage and a 'final exit door'.
FRA was a privately paid consultant.
Is timber in walls not usually covered by a layers of fire resistant plasterboard, and undersides of stairs also layered in plaster/board, stair carpet coverings being fire retardent. Would not any self respecting FRA expect to see such ?
Should Wago start making CU's ? ... a terminal that comes loose when in service (and I have experienced a few) ... how is that allowed as an acceptable method of gripping a cable ... my electrician is very wary of Wagos' however.
Fixing of cables in escape route walls and ceilings, terrible to think firemen lost lives because of the lack of fire rated clipping methods, and was there not debate around the use of nylon plugs with such fixiings.
A domestic dwelling configured as an HMO will have 'protected escape routes', with emergency lighting, signage and a 'final exit door'.
FRA was a privately paid consultant.
Is timber in walls not usually covered by a layers of fire resistant plasterboard, and undersides of stairs also layered in plaster/board, stair carpet coverings being fire retardent. Would not any self respecting FRA expect to see such ?
Should Wago start making CU's ? ... a terminal that comes loose when in service (and I have experienced a few) ... how is that allowed as an acceptable method of gripping a cable ... my electrician is very wary of Wagos' however.
Fixing of cables in escape route walls and ceilings, terrible to think firemen lost lives because of the lack of fire rated clipping methods, and was there not debate around the use of nylon plugs with such fixiings.
Indeed - but unless you forgot to tell us, I didn't think we were talking about an HMO.
Timber in domestic premises usually is covered by fire-resistant materials, but unless the wall is classified as a fire barrier, I don't think there is any requirement for such. Similarly with doors, door frames etc. in residential properties - unless they are required to be 'fire doors' (which many probably would in an HMO, or multi-storey house), I don't think there are any fire-related requirements (indeed, with the modern fashion for 'open plan living', doors are somewhat of a rarity in some houses! ... and wooden floors, stairs etc. are not necessarily covered with anything (again, 'bare wood' has regained some popularity)
I suppose that depends of the commissioned scope of the inspection, and what regulations he/she was meant to be inspecting in relation to.
Indeed - and, as I said, I'm a little 'wary', too - but that's probably just me (plus your electrician
). As I wrote:I suspect there is some room for debate here. If you look around most domestic properties, there are usually few, if any, cables that would be likely to 'fall' and entrap fire-fighters unless/until far more catastrophic bits of the building's structure had already fallen onto them.
Kind Regards, John
Any cable around the edge of a room or in a ceiling where it doesn’t run thru joists is a risk to a fireman
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That's what people say but, as I said, I find it hard to picture many situations where it would be a problem - a cable going up one side of a door frame, across the top and then down the other side would be one example I can think of. However, in general, any cable goes from somewhere/something to somewhere/something else, and those things will stop the cable falling u less there is structural collapse - in which case I would have thought that the fire-fighters would be dealing with much greater hazards than just cables.
Could you perhaps give some examples (other than up and across the top of a door frame) where the hazard you are talking about would/could arise?
Kind Regards, John
I think you need to remember ceilings collapse easily.
Cable has slack and then will hang down.
Cable has slack and then will hang down.
True, but, in my experience, there is very rarely enough slack to hang down low enough to cause any real problem. Indeed, rarely enough slack to prevent me cursing when "I need a little bit more"
Kind Regards, John
Interestingly I've always considered above a plasterboard ceiling as concealed within the fabric of the construction, rather than understrung below something and comming in the realms of things that need metallic support. I think if you were to do differently then just about every domstic rewire would be non-compliant. Its a differnt situation with the T bar grid ceilings, they are not known to last long in a fire situation and cabels are more likely to hang down because they can run all directions unsupported, rather than one direction unsupported, but if they have to traverse at 90 degrees to that, they are either drilled through joists if tehre is a floor above, or go over teh top of them in an attic.
Even before 2015 it used to be a ****take how installers would install above them, one of the best I found was a 25mm SWA which run across the grid in a department store to supply a consumer unit in the home electronics section for the television display... how they drew it in without collaspsing the ceiling I don't know....the why is far easier... the top of the void space was many metres above, and the only way to it to fix support was to dismantle a section of ceiling sufficent that a siccsor lift could pass through it and then re-assemble afterwoods (or get a ceiling grid company to do so)
Even before 2015 it used to be a ****take how installers would install above them, one of the best I found was a 25mm SWA which run across the grid in a department store to supply a consumer unit in the home electronics section for the television display... how they drew it in without collaspsing the ceiling I don't know....the why is far easier... the top of the void space was many metres above, and the only way to it to fix support was to dismantle a section of ceiling sufficent that a siccsor lift could pass through it and then re-assemble afterwoods (or get a ceiling grid company to do so)
Indeed so - and to 'adequately support' those above-ceiling cables that run parallel to the joists could presumably add appreciably to the amount of work/cost involved in a domestic re-wire.
As I've said, I'm still inclined to think that, in most domestic installations, there will not be enough slack for above-ceiling cables to fall far enough to be much of a problem if the ceiling collapses. I may be wrong, but I think that, in general, DIYers (like myself) tend to be more generous about 'slack' (which is why the insides of CUs I've installed in the past look less neat that I would like!), whereas electricians tend to use little more cable then they have to!
The regulation, as it now exists, does seem to allow discretion in such situations. It merely requires that "Wiring systems shall be supported such that they will not be liable to premature collapse in the event of a fire." If one's judgement is that (e.g. because of lack of slack) the wiring is not liable to 'collapse' in the event of a fire, then I presume that no support/clips/whatever is required. In any event, it would seem to be next-to-impossible to police much of the regulation, since the majority of the wiring we're talking about will not be available for (a practical degree of) inspection) after they have been installed. That's a bit like cables within walls - there is no practical way of inspecting the route after installation.
My only personal experience of such ceilings in domestic properties (I have two in my present house) are 'illuminated' ones (i.e. translucent panels, with a light above) - and with those one cannot, for aesthetic reasons, have cables laying loosely on them.
Interesting. In general (and certainly in the case of 25mm SWA!), commercial premises such as you describe usually have very high ceilings (and presumably not vast amounts of 'slack') so I would not have thought that even with total collapse of the ceiling the cable would 'droop# down far enough to get in the way of fire-fighters or others?
Kind Regards, John
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I disagree with that, although often not installed for the purpose of fire rating, plain Gyproc WallBoard has a 30 minute fire rating which should be more than sufficient to eliminate the need for any special fixings above a ceiling.
That depends on the cable remaining fixed to the top of the wall at both sides of the room.
Indeed - but, as I said, a cable will always go 'from somewhere to somewhere else' (holes in masonry walls, accessories etc.). If it becomes detached from one of those 'ends', and is not otherwise contained, then it will obviously 'fall' but (a) assuming it's above a ceiling, then one is then considering at least two major things having gone wrong (collapsed ceiling and disconnection of cable and (b) if a cable falls and 'dangles' because one end has been disconnected, then I would not thought it would represent all that much of a (mechanical) hazard to fire-fighters (or others) - I would have thought that it's when a 'loop' (facilitated by slack) 'dangles down' that there is an appreciable risk of 'entanglement.
One would hope to be able to look to the fire brigades for their judgement about the nature and extent of the hazard, and any action required it address it - but they really need to earn our confidence and trust before we can rely on them in that way. If I believed that there was a rational and reasonable basis for them requiring that tens of millions of domestic CUs should have 'non-combustible' (but not 'fire-containing') enclosures, then I would probably be much more inclined to take seriously whatever they had to say about cable support!
Kind Regards, John
30 minutes is completely inadequate.
Firefighting activities do not cease 30 minutes after the start of a fire.
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If the fire is sufficient that the ceiling is down, the room is going to be unsuitable to use as a walkway anyway.
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