New gas pipe run

[jpdw]

We will be having an old boiler replaced next year. Our plumber has indicated that a new bigger gas pipe is needed to it. I've no problem with this as (1) we know him and (2) reading on here there seems to be a lot of genuine requirement to upgrade older gas pipes.

We did not discuss possible routes, but I am now wondering about what may be the different options as I am planning a complete refurb of the kitchen via which the first half of the pipe will run.

The boiler itself is at the far end of our conservatory, so concrete floors & no ceiling void. The current pipe run through the conservatory is behind the skirting.

Q1: Am I correct to assume that running gas behind skirting is a no-no (for same reasons as electric..... chances of hapless people bashing nails etc through it).

On this assumption, we need to run the pipe elsewhere but the wall layout means it's not easy to find a good short low-visibility route without adding heaps of bends.

Q2: Can the gas pipe (or the 3.5m "across" the conservatory be run outside, attached to the conservatory's brick wall? If yes, are there any special rules/regs that would need to be considered (ie pipe must be boxed in / labelled / painted bright yellow (joke) etc,...). The wall (and 6 inches beyond it) is on our property though only accessible via our (friendly) neighbours (ie we can have access to it if/when needed for maintenance).

Thanks !

 

[Bahco]

Gas pipes can be run outside and are labelled with yellow tape marked Gas.

 

[Agile]

The normal thing would be to ask your CORGI registered installer.

It seems that you do not have confidence in his capabilities. If that is the case should you not get someone else who you feel more comfortable trusting his advice?

Tony

 

[jpdw]

The normal thing would be to ask your CORGI registered installer.

It seems that you do not have confidence in his capabilities. If that is the case should you not get someone else who you feel more comfortable trusting his advice?

Tony

Actually, we do have confidence in him - in fact he's refurbed our whole CH/HW system & has done our regular boiler services for 6 years at our last place -- so we have full confidence in his abilities, skills etc, and (if it helps indicate our level of confidence/trust) I'd have no problems giving him the house keys when he does this job.

When he had a look at our old old boiler, we had an initial discussion about the boiler change and mentioned the need to fit a new gas pipe but we didn't discuss the actual run. At the time I (and perhaps he too) assumed that when we found the old gas route it could simply be upgraded... a couple of months later, I'm now much more aware of cable & pipe runs in the property and have found that the gas is behind the skirting board and so now think we would need to find a new route (if my assumption that behind skirting=bad is correct).

We are looking at this work next year (soon as we dont need the rads on) as part of having the kithen re-fitted, new CU, kitchen walls & ceilings plaster replaced etc,,.... so the question was just to establish the options while we do some initial planning for the whole thing.

My question was simply because I didn't know if running the pipe externally was allowed at all.

Now I know outside is a legal possibility, I can consider if that would be disadvantagous because of other parts of the overall project (for instance... if run outside, where would it re-enter the property & if that is where we are planning to put a cupboard (say), then perhaps the outside route isn't so useful...).

Nearer the time, we'll go through full specs with him and yes, certainly will take & trust his advice on the run to use.

Thanks for your comments. Sorry if the original post gave anyone the impression we weren't happy with the guy because that is definately not the case. Just that we didn't go into any details.

 

[ChrisR]

You can put them outside, they don't normally need marking or protecting unless in a driveway or similar.
If you use brass clips they weather down with the pipe to a brown you don't really notice. If you use white plastic clips they look horrid and then drop off when the UV gets to them!
They can be buried in concrete and similar screeds (with conditions).
No reason why it couldn't go behind a skirting imho. If you thought someone might hammer random nails through your skirtings then you could use steel pipe!
I've also see them hidden behind ceiling coving very well.

 

[jpdw]

Thanks folks.

Interesting to learn that it's probably not verbotten to pop the gas behind the skirting. Still, I'll try and avoid it if our corgi guy can get a better route. (Not even sure if the larger pipe required would fit in the gap behind the skirt.)

Anyway... thanks all for the input.

jon

 

[Gasguru]

You would find it very difficult to comply with the 25mm clearance to electrical cabling.

Since the pipework is likely to be 22 or even 28mm channelling out sufficient depth in the wall is unlikely to comply with building regs. Maximum chase depth is the wall thickness (typical 100mm) /6 ie 17mm. The pipes must then be covered to fully seal them.

You can get profiled skirtings that may help.

 

[jpdw]

You would find it very difficult to comply with the 25mm clearance to electrical cabling.

Finding it difficult to comply, is, I assume why the original installer didn't bother trying... I've not taken the whole skirt off, but lets just say that I am pretty confident the existing 15mm is less that 25mm from the nearest elec cable.

Since the pipework is likely to be 22 or even 28mm channelling out sufficient depth in the wall is unlikely to comply with building regs. Maximum chase depth is the wall thickness (typical 100mm) /6 ie 17mm. The pipes must then be covered to fully seal them.

I didn't know the /6 rule - but it makes sense otherwise you'd chase the whole wall depth out ! From how I've seen the circulator pipes (higher up the wall), I think the gas is probably chased into the wall (inner skin blockwork) some mm but then gets extra "depth" because the plasterboard & skim coat stop short... Still, I doubt 22 would fit there...

You can get profiled skirtings that may help.

Thanks Gasguru.. that's another possible option to consider.

 

[chrishutt]

You can always bring the skirting board out further from the wall on battens to get more depth. Also the 25mm clearance from electrical cables is not required if the gas pipe is insulated, so running behind the skirting isn't necessarily such a difficult option.

 

[corgiman]

where does this bit of the regs stand on when a gas pipe joins a gas valve?

most of em are connected to 240vAC, how do we keep the gas 25mm away from them

 

[chrishutt]

And it's common to find electrical cables laying alongside or draped over gas pipes. I've never heard of any problem arising from it. I suppose in theory if the cable insulation broke down and the gas pipe wasn't earthed you could end up with a live gas pipe, but that could apply to copper water and heating pipes in general.

 

[giblets]

CH, I think it's more a question of the insulation breaking down on the cable and causing arcing to the (earthed) gas pipe thereby punching a hole in said pipe, releasing gas from within to be ignited by the attendant spark.

Or so a £ORGI Inspector once told me.

 

[corgiman]

CH, I think it's more a question of the insulation breaking down on the cable and causing arcing to the (earthed) gas pipe thereby punching a hole in said pipe, releasing gas from within to be ignited by the attendant spark.

Or so a £ORGI Inspector once told me.

Giblets I concur with your and add one off my own to your last statement

 

[chrishutt]

CH, I think it's more a question of the insulation breaking down on the cable and causing arcing to the (earthed) gas pipe thereby punching a hole in said pipe, releasing gas from within to be ignited by the attendant spark.

Or so a £ORGI Inspector once told me.

Ah yes, I hadn't thought of that. Has anyone ever heard of it happening?

 

[ChrisR]

The skirting could simply be put back on with some packing to accommodate a thicker pipe. There's often 20 - 25mm of plaster, drywall + dabs, or whatever. That part isn't structural. Any vapour barrier should extend behind the pipe.
I was told to teach that the 25mm gap is about access to the pipe/wire without disturbing the other. Part of the ACS faults rig has a cable inside a plastic conduit, within 25mm of the pipe, which would scotch Giblets' reason.
I previously assumed it was to do with banging a nail through both at once.