Help! I’ve lost my gas pipe!

[Adsibob]

Wall has been bordered up and partially plastered. Lost the photo showing location of copper gas pipe. Need to know fairly precise location as wall is to be covered with wall mounted cabinets. I know roughly where the pipe comes into the house from the outside. I also recall it then travels upwards in a vertical line, before making a right angle and travelling horizontally across the wall. But I don’t know the point on the wall where that right angle is.

 

The relevant wall construction is

 

 

i think the copper pipe is in the ventilated cavity, rather than in the service void. So from the inside of the house, it is behind the aluminium. 
 

Potentially complicating matters, we used metal (I presume steel) studwork, directly behind the 12.5mm plasterboard, so a metal detector might not be able to distinguish between the studs and the vertical pipe. I say “potentially” because I’m hoping there are metal detectors which can detect non-ferrous metals such as copper, whilst ignoring ferrous ones such as steel.

 

Are there such metal detectors?

 

Any other tricks of the trade to locate a hidden pipe?

[joth]

6 hours ago, Adsibob said:

Any other tricks of the trade to locate a hidden pipe?

Smash a long masonry nail through the wall in the place you least think the pipe will be. Guaranteed to locate it.

 

You could try running the gas appliances on max and then using a thermal camera. It may show a cold line.

 

If you're covering the walls in cabinets you have scope to make some exploratory holes through the finishes to locate it. It'll all be covered up anyway.

 

Love how electrics have safe zones that ban random 90° bends but a gas pipe you can put wherever you want. 

I don't suppose there are any sockets on that wall and they're lined up to share safe zones of the pipe? Not sure if that'd be legal but on one level it does make sense. 

Edited December 16, 2022 by joth

[Adsibob]

1 hour ago, joth said:

Smash a long masonry nail through the wall in the place you least think the pipe will be. Guaranteed to locate it.

 

You could try running the gas appliances on max and then using a thermal camera. It may show a cold line.

 

If you're covering the walls in cabinets you have scope to make some exploratory holes through the finishes to locate it. It'll all be covered up anyway.

 

Love how electrics have safe zones that ban random 90° bends but a gas pipe you can put wherever you want. 

I don't suppose there are any sockets on that wall and they're lined up to share safe zones of the pipe? Not sure if that'd be legal but on one level it does make sense. 

Thanks. There is one socket on the wall, but it is nowhere near the pipe. The plasterboard is mostly unplastered so pretty easy to cut into it to explore, problem is that i think the pipe is behind the Tyvek foil and I don’t want to compromise that. I guess the thermal imaging camera could work, but would prefer a metal detection solution.

[Russell griffiths]

How heavy are these cabinets ?

i would be thinking that that wall should have a sheet of ply on it before plasterboard, if so pull the plasterboard down, locate pipe, plywood and re plasterboard. 

[Radian]

1 hour ago, Adsibob said:

but would prefer a metal detection solution.

Unlikely to find one that can discriminate between copper and steel unless the pipe is so close to the surface that you can adjust the sensitivity right down.

 

But gas flow is quite noisy - perhaps if you whack on a lot of gas, you might be able to hear it - got a stethoscope?

[SteamyTea]

6 hours ago, joth said:

Love how electrics have safe zones that ban random 90° bends but a gas pipe you can put wherever you want. 

Not sure you can.

 

https://www.legislation.gov.uk/uksi/1998/2451/part/D/made

 

Enclosed pipes

19.—(1) No person shall install any part of any installation pipework in a wall or a floor or standing of solid construction unless it is so constructed and installed as to be protected against failure caused by the movement of the wall, the floor or the standing as the case may be.

(2) No person shall install any installation pipework so as to pass through a wall or a floor or standing of solid construction (whether or not it contains any cavity) from one side to the other unless—

(a)any part of the pipe within such wall, floor or standing as the case may be takes the shortest practicable route; and

(b)adequate means are provided to prevent, so far as is reasonably practicable, any escape of gas from the pipework passing through the wall, floor or standing from entering any cavity in the wall, floor or standing.

(3) No person shall, subject to paragraph (4), install any part of any installation pipework in the cavity of a cavity wall unless the pipe is to pass through the wall from one side to the other.

(4) Paragraph (3) shall not apply to the installation of installation pipework connected to a living flame effect gas fire provided that the pipework in the cavity is as short as is reasonably practicable, is enclosed in a gas tight sleeve and sealed at the joint at which the pipework enters the fire; and in this paragraph a “living flame effect gas fire” means a gas fire—

(a)designed to simulate the effect of a solid fuel fire;

(b)designed to operate with a fanned flue system; and

(c)installed within the inner leaf of a cavity wall.

(5) No person shall install any installation pipework or any service pipework under the foundations of a building or in the ground under the base of a wall or footings unless adequate steps are taken to prevent damage to the installation pipework or service pipework in the event of the movement of those structures or the ground.

(6) Where any installation pipework is not itself contained in a ventilated duct, no person shall install any installation pipework in any shaft, duct or void which is not adequately ventilated.

[ProDave]

Not meant to be serious:

 

Turn gas off.

 

Drill hole.

 

Turn gas on.  Can you smell gas from the hole?  If you can you know where the pipe is and where to repair it.  If not, you missed the pipe. Hang the cupboard.

 

For a final sanity check, get a gas safe engineer to do a drop test, just in case you grazed it and made a minute hole.

[Jilly]

Buy a freestanding cupboard from eg Neptune…?

[Alan Ambrose]

If you’re gentle with a drill bit through the plasterboard and don’t use over-long fixings, you can finesse it. Pipes and cables are not generally right behind the plasterboard. You can even try drilling through a bit of old gas pipe with the bit you intend to use to get a sense of ‘what does it feel like to hit a pipe’. Are you not going to pick up the studs for a secure fixing anyway? What fixings are you using?

 

A borescope might be another more technical solution.

 

i think, in practice, most kitchen fitters have little idea what’s behind the plaster - how would they?

 

Alan

[ProDave]

2 hours ago, Alan Ambrose said:

i think, in practice, most kitchen fitters have little idea what’s behind the plaster - how would they?

They certainly don't seem to understand safe zones.........

[Adsibob]

8 hours ago, SteamyTea said:

Not sure you can.

 

https://www.legislation.gov.uk/uksi/1998/2451/part/D/made

 

Enclosed pipes

19.—(1) No person shall install any part of any installation pipework in a wall or a floor or standing of solid construction unless it is so constructed and installed as to be protected against failure caused by the movement of the wall, the floor or the standing as the case may be.

(2) No person shall install any installation pipework so as to pass through a wall or a floor or standing of solid construction (whether or not it contains any cavity) from one side to the other unless—

(a)any part of the pipe within such wall, floor or standing as the case may be takes the shortest practicable route; and

(b)adequate means are provided to prevent, so far as is reasonably practicable, any escape of gas from the pipework passing through the wall, floor or standing from entering any cavity in the wall, floor or standing.

(3) No person shall, subject to paragraph (4), install any part of any installation pipework in the cavity of a cavity wall unless the pipe is to pass through the wall from one side to the other.

(4) Paragraph (3) shall not apply to the installation of installation pipework connected to a living flame effect gas fire provided that the pipework in the cavity is as short as is reasonably practicable, is enclosed in a gas tight sleeve and sealed at the joint at which the pipework enters the fire; and in this paragraph a “living flame effect gas fire” means a gas fire—

(a)designed to simulate the effect of a solid fuel fire;

(b)designed to operate with a fanned flue system; and

(c)installed within the inner leaf of a cavity wall.

(5) No person shall install any installation pipework or any service pipework under the foundations of a building or in the ground under the base of a wall or footings unless adequate steps are taken to prevent damage to the installation pipework or service pipework in the event of the movement of those structures or the ground.

(6) Where any installation pipework is not itself contained in a ventilated duct, no person shall install any installation pipework in any shaft, duct or void which is not adequately ventilated.

Well they complied with this, but I still lost it! Why doesn’t the legislation say something like “No person shall install any installation pipe work in a wall, without photographic records showing the exact position of the pipe in the wall”.

Edited December 16, 2022 by Adsibob