How deep should a gas supply pipe be below a concrete floor?

[MrD]

Hi,

That should cover it, apart from pointing out - as safety concious as you all seem to be, quite rightly - that I don't intend doing any gas plumbing.

The pipe crosses the living room floor in a channel at a depth of about 1-2", which has then been covered with concrete. It's clear that the concrete covering the pipe is cracked. I think it might be a good idea to first find out how it should be done and secondly, get it fixed.

A link to regulations would be great.

Is the appliance fitter obliged to either refuse to fit the appliance or correct this issue (at my cost) ?

Pipes buried under concrete need to be protected from direct contact to prevent corrosion and plastic covered pipe is normally used, or in some cases, the bare copper is covered with tape. Could I re-concrete that pipe myself?

Thanks in advance,
Mark.

 

[ChrisR]

BS6891 but you won't find a link. It doesn't say much, mostly example pictures.
There's no specific depth, but as you say the pipe must be protected agin corrosion. It isn't really prescripitve in detail, leaving the responsibility to the installer, as usual.
No compression joints, "minimum" solder joints.
Protective tape may not be acceptable as it doesn't provide scope for movement. For "soft coverings" Corgi stipulate 5mm, though they also mention protective tape, which wouldn't normally be 5mm thick. Pipes with Tees in are a much bigger problem on movement. A straight pipe a metre long isn't likely to be a problem. Installer's call.

Plastic ducting is good, as is a duct with a plywood lid.
They suggest factory sheathed pipe, with wrapped joints in a larger plastic sleeving, but don't say you can't use unsheathed pipe if it's in a sleeve.
Think carpet nails regarding depth!

I wouldn't worry about a crack in the concrete.

 

[towman]

Depends how much work they want to do - applying these regs every house on my estate would need the floors and walls digging up to replace the copper pipe buried in the concrete - and the T's buried in the floor too!

I've had 3 CORGI blokes in to service and install appliances and one to repair a pipe damaged by a nail - (which I didn't do !!) - none of who have been in the least bit bothered by the bare unprotected copper supply buried in the wall and floor. The one reparing the pipe just cut out the damaged section and replaced it with more bog standard copper pipe! As it was the middle of the cold spell in Feb and we were due to go on holiday a couple of days later I did not ask about pipe protection! I reckon we'd be lucky if the pipes were any more than 10mm below the screed surface!

 

[MrD]

Thanks for the responses, guys.

It sounds like my situation is no different to many other instances - perhaps worryingly so!! - but I can probably carry out some additional reinforcement unmolested.

The existing cracks are such that in bare feet it's possible to detect a dip in the floor, with underlay and carpet in place . I can't imagine this is good enough.

Underneath the concrete, the pipe is laid on and covered with sand, presumably to protect from the concrete? Some kind of 'soft' protection from concrete seems a good idea?

Plastic ducting sounds ideal, only if I can fit it over the fitted cap and into the space available. Or split the duct and fit it that way... hmm

I think a similar / better repair to what's existing will be fine, the old concrete seems just to be too thin a layer.

Many thanks,
Mark.