Capping or No Capping?

[eveares]

I always use plastic conduit (Not capping). It is possible to replace a cable in the future, if you are very careful and have access to the other end of the conduit. Fix it as required with plumbers banding.

But surely that would de-rate the cable as it would then fall under reference method B or possibly A?

 

[eveares]

Chased and plastered I would use capping

Block then dot and dab I would just clip

OK, but would you use galvanised or PVC capping?

 

[sparkwright]

OK, but would you use galvanised or PVC capping?

PVC every time.
Galvanised is harder to work with. For a start, the manufactured edges are often so sharp you can barely pick the stuff up.
Then you've got to either nail through the sides, which is extra effort.
Or if you don't want to nail through it, you have to nail just near to the sides, and probably have to mess about with washers to do this.
Then you have to ensure any cuts you make in the capping are nicely filed to prevent it snagging the cable.
Also, if you should need to make any alterations to it in the future, for whatever reason, it's going to be a nightmare to cut into it.

I would strongly suggest you use PVC.

 

[pete01]

OK, but would you use galvanised or PVC capping?

I always use metal, I cut it with tin snips and fold the rough edge over with long nose pliers.

I use screws and penny washers to fix it (capping nails are rubbish)

It can be a pain but it's just what I'm used to.

 

[ebee]

My Tenpenorth,
If I am chasing out and doing the plastering (at least one sufficient coat) then just clip and no capping.
If it`s going to be left open a while or I do not really trust the plaster then I would cover it by some means capping/conduit/ a big heavy door as relevant, protects the cable if other persons or other trades are about.
Metal capping no, you always have sharp edges however much you file them, bending a lip on the end does help a bit. Those sharp metal edges and somebody trying to replace cable without disturbance is usually potentially a route to possible disaster.
I`d rather plaster in without capping and force a hack out and replaster.
If you decide on capping I would use plastic.
My real preference though would be to use conduit if anything at all whether oval or round there are pros and cons one v tother.
as an alternative to clipping/banding the conduit you can drill a hole thru it small enough to allow a screw thread in (so you now effectively have two tiny screw holes at opposite sides of the conduit.
of each of the pairs of holes open up with a larger drill all on the same side of course.

You can the drill and plug the wall then screw from the large hole to the small hole and your screw head disappears past the front wall of the conduit and sits on the back of the inner wall so the conduit is firmly in place with just a few , screw head size holes on the conduit front and you can then thread your cable in mostly protected.

Then let your plasterer loose when you like.
Probably the best option if you need to.

I will read this one again later because I think it sounds more complicated than it actually is.
Hope you know what I mean.

PS mentions of bits of wire/splinters of wood etc etc for temporary bridging whilst some plaster sets sufficiently is a method employed a few times.
Similarly slate lathe as a wooden bridge allows you to put plastic spacers (T & E Sheath offcuts) under the wood bridge section and the plater around sets then when bridge removed can have a sufficient depth for new plaster over those small sections of cable. Especially useful for old plaster outside the chases and or hard or difficult walls. Some one coat plasters or bonding can be quite strong enough.

I don`t like metal capping - remember the shower cable I mentioned finding quite a while ago causing an "Ouch " live wall when nail thru then removal and a lightly damp wall.Tiny shards of the pin hole making continuity of the L cable to not just the surrounding tiny are but now the whole of that wall beneath the shower above the bath had a nice big conductive capping just below the wallpaper, slight moisture on paper and a tingle or an ouch.

 

[flameport]

But surely that would de-rate the cable as it would then fall under reference method B or possibly A?

Using oval or round conduit will result in method B in most cases.
For most normal domestic circuits this changes nothing.

Round conduit if space allows, oval if not.
Capping is pure junk and has no purpose other than to cause bother and annoyance to all.

 

[Harry Bloomfield]

Seems right enough to me That's what I'd do, but wouldn't necessarily even use formal 'clips' - I might well just 'jam it into the chase with 'bits and pieces' (sometimes little bits of T+E!), maybe nails, to keep it in place until it was plastered over.

I not ever done much of it, but when I did, I would be doing the patch plastering. Cables would be clipped, wedged, or whatever held them in place long enough to get a first coat of plaster on. I would even use odd bits of plaster, to stabilise sections of cabling, let it go off, then later do the rest of the first coat.

Better than fairly thick T&E, where depth was at a premium, would be that flat, very tough plastic strapping, you often see discarded. The stuff they use for holding things tight together on pallets, and sometimes heavy parcels. It's thin, extremely tough, and takes a nail well.

 

[JohnW2]

Using oval or round conduit will result in method B in most cases. For most normal domestic circuits this changes nothing.

True. Off the top of my head about the only thing it would (strictly speaking) definitely preclude would be a 25A 2.5mm² radial.

In terms of strict compliance with regs (albeit not really an issue in practical terms) there would undoubtedly be debate (and disagreement!) as to whether Method B 2.5mm² (CCC 23A) would be acceptable for an unfused spur to a double socket from a ring final - the debate depending upon whether or not one believes that a double socket could theoretically represent a 26A load.

 

[JohnW2]

I not ever done much of it, but when I did, I would be doing the patch plastering. Cables would be clipped, wedged, or whatever held them in place long enough to get a first coat of plaster on. I would even use odd bits of plaster, to stabilise sections of cabling, let it go off, then later do the rest of the first coat.

Indeed. I could have written all of that myself, in relation to what I normally do.

It must be a case of "Great Minds ..."

 

[ebee]

Round conduit if space allows, oval if not.
Capping is pure junk and has no purpose other than to cause bother and annoyance to all.

Well said that man!

 

[ebee]

PS - its not common to see "clip-plugs" these days either as far as I know.

 

[pete01]

Steel capping is for everyone, you have to know how to do it....some dont

 

[eveares]

Using oval or round conduit will result in method B in most cases.
For most normal domestic circuits this changes nothing.

Round conduit if space allows, oval if not.
Capping is pure junk and has no purpose other than to cause bother and annoyance to all.

Except a 4mm radial (like I have in my kitchen) would de-rate the cable to 30A which is less than the 32A over current protective device typically used these days. Not many 30A RCBO's/MCB's around as far as I know.

 

[sparkwright]

Using oval or round conduit will result in method B in most cases.
For most normal domestic circuits this changes nothing.

Round conduit if space allows, oval if not.
Capping is pure junk and has no purpose other than to cause bother and annoyance to all.

Capping is better than oval conduit on new builds - because it tends to be shallower than most oval conduit sizes, and so when fixing direct to block it means you can get a thicker covering of plaster over it so less chance of cracking.

 

[JohnW2]

Except a 4mm radial (like I have in my kitchen) would de-rate the cable to 30A which is less than the 32A over current protective device typically used these days. Not many 30A RCBO's/MCB's around as far as I know.

Ah, yes, I missed that one. As you will have seen, I thought of the 25 A 2.5mm² radial, and also pondered about an unfused spur of 2.5mm² feeding a double socket (about which opinions will undoubtedly vary!), but I 'missed' the 32A 4mm² radial. Thanks for having a better mind than mine