ELV comms, ariels etc - how many faceplates?

[Tim S]

You can never have too many.

But cometh the day you have to actually chase the walls out, then any are "too many".

Seriously...

I'm planning to put a double 13A socket about every 2m round every wall, bar the shortest walls in some rooms. That's easy - just a long horizontal chase with a few ups for doorways.

I'm also thinking about putting all my ELV stuff in as double euro-mod plates above certain 13A sockets. Then two bits of wide-ish oval conduit up to the ceiling. I'll drop the cables in later, when it becomes clearer where we want arials, Cat5e, loud speaker wires etc. And you can get a euromodule for just about anything.

So this is IMHO a good flexible approach and it's easy to pull and refeed a different cable later (will be floorboards upstairs). The reason for "above the 13A sockets" to avoid LV and ELV crossing in the same box (bad from

17th Regs, bad for interference).

I won't be flood-wiring the lot straight away. So given the only downside is the number of backboxes I need to sink into plaster/brick, does the panel suggest one such assembly above every 13A socket, or one every two 13A plates? Corner positions will be a priority.

Cheers

Tim

[Tim S]

Tim S coughed up some electrons that declared:

Just to clarify - double plates, so 4 euromod positions per plate

[Andrew Gabriel]

The US wiring regs have a good rule in this area. Can't recall the exact figures, but it's something along the line of you must be able to plug in an appliance with a 6' cord positioned anywhere along the edge of the room without the cord tailing across a doorway.

Something I did in a few places where I might want back boxes in the future was to sink the box in, put a piece of stiff card in the front (waterproofed with parcel tape), and then skimmed over them when skimming the wall. It avoids having blank plates on the wall, but I can tap that with a hammer to break out the plaster when the box is needed. Broken out two of them so far (and none have broken out by themselves).

[BigWallop]

Wouldn't it be easier to fit 3 compartment skirt or dado trunking? Then you'd have any amount of sockets and control wiring you wanted in each room, with very little alteration or upheaval. Or sink 3 div' metal trunk in the walls and delivery everything through them. In the future changes you're sure to make, the wiring can be pulled through to each fixed point with a string.

[<me9]

The builders in a friend's house did that (but filled the box with plaster over the wires) for one socket on the ring main (in about 1964). Recently when checking the wiring it took some considerable time to find where the break was in the ring. He now an an additional (very useful) socket on the landing.

I wonder wow much (if any) testing took place in those days.

[meow2222]

if youre replastering, I'd consider another option. Cat5e is very useful but can quickly get used up, conduit space ditto, so I'd put in conduit _and_ cat5e not in conduit. That keeps you a good amount of space free, and the fact that the 5e isnt conduitted is a non-issue.

How often to sink boxes? I'd only put them where I specifically wanted them, or was likely to. Whole lot of unneeded work otherwise. The main thing is to ensure the cable is there so a socket can be put anywhere at any future date.

I'll save the thread and incorp an idea or 2 here into the lv wiring article later.

NT

[Tim S]

Andrew Gabriel coughed up some electrons that declared:

Seems like a good rule of thumb.

Now that's a good idea. Actually, I was thinking of doing this with besa boxes in all the likely positions that anyone might want wall lights - eg both sides of every place a bed could logically go for one. Hadn't made the jump to doing it for comms.

Ideally, I'd have the plates on a level, but as I mentioned, I don't like the band I and II circuits getting too close, so over and above was the best compromise I could think of.

Cheers

Tim

[Tim S]

BigWallop coughed up some electrons that declared:

It would in an office, but I've yet to see anything that doesn't look pig ugly.

And skim plaster over the top? That would be an interesting idea. I could run the comms horizontally to the corner then take a bundle up, rather than a drop to every plate.

Do you have a link to any (google fails to oblige me, except for the plastic stuff)?

Cheers

Tim

[Tony Bryer]

Back home I ran all my cables in oval conduit with long horizontal runs (except at doorways obviously) so that at any time I could just pull out a cable between two sockets and cut a box into the conduit and rewire. Had to do it a couple of times - would have been a pain of a job if the cables were plastered in solid or just capped.

[Andrew Gabriel]

Trouble with BESA boxes is that lights don't all have their mounting screws aligned the same way. For potential wall lighting points, I've just run trunking down the wall with the cable threaded through. I can then cut through to them like Tony Bryer mentions for his sockets. The cables run up and into the ceiling roses, where they are not connected until such time as wall lights are installed. I have left a hidden BESA box in the middle of the bathroom ceiling, in case I ever want a light there (currently just has wall lights). The cable runs into the back of the fan isolator switch, where it's not connected.

There aren't many signals where cross interference is an issue nowadays. Modern signalling and protocols are designed on the assumption the data wires will be tangled up with the mains wiring. It's somewhat ironic that IEE got fussy about it just at the time when it ceased to matter.

[BigWallop]

Use "Compartment Trunking" as your search. There are a few makers / suppliers. CableLine, Gilflex and Mita come to mind as manufacturers.

Also, standard trunking can be compartmentalised by additional inserts, so it's worth a think about and research before committing.

[Lobster]

Isn't that oversimplistic? Better to consider what appliances will be likely to be used where, and plan accordingly?

Eg, I put 3 double sockets side-by-side under my computer desk, and already two sockets have 2-way adapters in. I could (and probably will) do similar in the corner of the living room, for all our a/v kit. But in the hall and landing (both of which are pretty large) there's just one double socket each, just for the vaccuum cleaner; have never missed not having more. Likewise down one whole wall in the living room, which is essentially a thoroughfare - can't imagine ever needing to plug in anything there.

David

[Tim S]

Lobster coughed up some electrons that declared:

Yes indeed - but all I wanted to do was given a general indication of socket density. Apart from the kitchen and specific locations that can take washing machines etc, our house doesn't have an obvious layout and even room purposes are flexible, which means that it's likely to get turned around several times in the next decade, especially as the kids grow up and usage patterns change. Heck, I arranged my uni bedroom in at least 3 different ways and it was only about 9' x 7'

Wall chasing and plastering is a yuk job, but right now the house is empty, so IMO better to spend a bit of extra time over-doing it now, because it will be hell to do after everything's moved in.

What I tend to do there is build the distribution into the cabinet (eg AV cabinet + TV, or computer desk) and manage with a single or pair of 13A plugs for a set of appliances.

It's the comms stuff I find one runs out of too quickly - eg: an AV point might contain: TV arial, radio arial, sat feed, ethernet (eg MythTv box) and a couple of loudspeaker endpoints (or more if one gets into Dolby).

It's not that I wish to wire every corner of every room with all that stuff, that would be silly. It's more like that I want to have the empty conduit and box on the end to accept it later. Lifting the upstairs floorboards (they will be laid and screwed with lifting in mind) and dropping in a few wires is OK, hacking the walls to death isn't.

Sorry if the above sounds curt, not intended and can't tell, got a bad headache :(

Cheers

Tim

[ARWadsworth]

I used architrave back boxes for cable entry points to my wall lights.

I had never thought about "overplastering" them.

Adam