metal conduit founder under plaster.

[tiffer]

Hello
I wonder if anyone can help. I am in the process of reinstating a fireplace into our Georgian property.
I have come across a metal conduit (pipe?) under the plaster. The metal is oval in cross section not circular. It runs diagonally across the corner of the brick arch. I imagine it would have been added at the time the fireplace was filled in or later.
I don't think it is a water pipe because of the shape of the metal, although my only reason for saying that is I haven't seen pipes that shape before. Could it contain electrical wires?
I have attached a photo which will I hope make it clearer. I have not yet taken the plaster back beyond the metal and I have not fully cleared the plaster from the pipe either. Has anyone come across anything like this before. All help and advice welcomed.

 

[steveb]

/bump back up to the top

Hard to tell I guess - my money is on it containing electrical wires as I have only seen cables inside oval tube - but no idea if they would be live or not... Usual precautions apply!

-Steve

 

[Moneypit]

Could it be the routing for a cable operated bell system? Bell pulls in every room in the house linked via cables and levers to the kitchen. Bell pulls were often positioned next to the fireplace.

 

[Flyfisher]

Welcome to the forum tiffer.

We have a fair bit of conduit under and over our walls and all the ones I've investigated have contained wires of some sort. Some were regular mains cables (and had fortunately been rewired with plastic wiring at some stage) and some were for door bells and were low voltage 'bell wire'. We also have one of those old 'annunciator' boards in the kitchen linked to bell pushes in most of the rooms and most of that wiring seems to be routed through metal conduit, although it is all low voltage.

So, my bet is the same as steveb and until you know for sure it would be best to assume they contain live wires and take the usual precautions.

Assuming you're not going to let this conduit prevent you from reinstating the fireplace, I would continue to expose the fireplace and hopefully find an 'end' to the conduit that might well join into a round junction box. These usually have a removable plate and you should then be able to open it up and discover what is really inside the conduit - again, being careful.

Are there any switches or sockets in the vicinity of the conduit?

 

[Feltwell]

Could be electrical - but could also be a feed to an old gas lamp, they were quite often fitted on chimney breasts. Does it look like it leads anywhere on the chimney breast? Any circular indentations in the plaster where an old lamp base could have been? This could easily be a later addition to your house as you say.

I keep finding gas lamp feeds in this place, small section iron tubing but it is round in section not oval, all thankfully long since disconnected!

 

[davidbrac]

wouldn't think its a bell pull as its too big and the angle too astute. But agree with the other comments on gas or electric. Agree that you should treat it as if it has live cables in it till you know different .

You need a process of elimination to figure this out . Are any floorboards been lifted where this goes up or down? or are there any sockets, light fittings etc in line with the run? If not look for marks of repair in the plaster work as that may indicate where a fitting was or where the run ends.

Oh yes welcome to the forum

 

[Keithj]

Hard to tell, looking at it. Electrical conduit in the latter half of the 20th century was circular, so that must be old, or was hammered into place!

As others have said, beware in case there are volts inside looking to escape. Trace it back to one end or the other and see what's there.

 

[philpjuk100]

Could it be edging bead for the plaster? You are not meant to run cables diagonally.

 

[Penners]

Could it be edging bead for the plaster? You are not meant to run cables diagonally.

My own thoughts exactly. If it were professionally installed electrical conduit, it should run vertically down the wall - although I've no idea how long ago that rule was introduced. I also wondered whether it was plastering bead, but it looks a bit chunky for that. And for both these suggestions, why have it cutting partway across the corner of the fireplace?

So I'm afraid you're no farther forward, tiffer. Electrical, gas, annunciator... all are possible with arguments for and against. I can only suggest that (a) you do nothing to cut into or damage the pipe for the time being, and (b) you trace its route until you come across some more definite indication of its identity.

One more thing - please tell us when you discover anything that might solve the mystery!

 

[Zebra]

Electrical conduit in the latter half of the 20th century was circular, so that must be old, or was hammered into place!

Not necessarily. It would have been round if used as a contained conduit system, but if used to protect sheathed cables it was often oval.

If it were professionally installed electrical conduit, it should run vertically down the wall

Not necessarily! Very often they weren't, even if they were supposed to be!

I would place money that it's electrical conduit. It may or may not contain live cables. Even if the house has been rewired in the last couple of decades, they may have reused old conduits. We still do that if we have to.
Yes cables should run vertically, but that don't mean they do!
I'd second what several people have said, follow it until you get to an end, and see what's in it!

 

[Keith Bowman]

You might be able to trace where it goes with a pipe/cable detector without having to hack off plaster all the way.

 

[Penners]

Zebra - I have one of those voltage detector pens, which can be very useful for finding buried cabling and determining whether it's live or not. However, I have severe doubts whether it would work through metal conduit. Can you clarify this for me, please? If I'm wrong, and it will work through metal, it might banthe ideal gizmo for tiffer to use.

 

[Zebra]

Naa, won't work through metal conduit...

 

[philpjuk100]

If it is "in the way" why not turn off the power (and the water) and remove it?.

 

[Penners]

Naa, won't work through metal conduit...

Mmmm - I feared not.

 

[Owain]

If it is "in the way" why not turn off the power (and the water) and remove it?.

and the gas

Although for very old metal oval my guess is it's tube for a mechanical bell wire.

 

[Penners]

Oh no! If the tube and its wire are removed, how will one summon the upstairs maid when one needs her services?

 

[Flyfisher]

Naa, won't work through metal conduit...

Indeed, though a plain metal detector should work, whether any cable is live or not.

Actually, I've only thought of those voltage detector thingummies as a safety device, to save drilling through a live cable, rather than a detection device.

Something like this?
http://www.amazon.co.uk/Draper-63401-Combined-Voltage-Detector/dp/B0001K9YB0

Hmm, I see these now detect voltage as well. My version is metal and stud only - bit it is very old!

 

[Owain]

Oh no! If the tube and its wire are removed, how will one summon the upstairs maid when one needs her services?

You'll just have to whistle out the bedroom window and hope that the gardener's boy is obliging.

 

[Penners]

Something like this?
http://www.amazon.co.uk/Draper-63401-Combined-Voltage-Detector/dp/B0001K9YB0

Not quite, FF. I have a multi-detector like that, but the thing I'm talking about is:-
http://www.screwfix.com/p/fluke-1ac-ii-voltage-detector-pen/85949

This is far more precise. Not only can you detect voltage, but if you hold the tip against a cable, you can tell which side of the cable is live and which is neutral. You can also check a socket for polarity without inserting anything into the socket, you can check a cable run to find out where there's an internal break... and so on.

It's a tool I don't use often, but when I do it's invaluable.