Gas Supplies passing through communal areas or other properties must comply with British Standard (BS) 6891(1), IGEM/UP/7 Edition 2(2) and, where necessary, manufacturer’s installation instructions. Guidance for gas in flats and other multi-occupancy dwelling buildings can be found in IGEM/G/5(3). Existing Installations can in some circumstances be classified as Not Current Standards. In other circumstances upgrades to current regulations will be necessary, consult your Gas Safe Registered Engineer. If conversions of buildings or gas pipe installations are carried out post the date of regulations came in force then compliance is mandatory regardless.
If the pipe is moved or altered it must comply with current standards.
If a gas pipe were to pass through the another flat or property, a communal area or any area classified as a "Protected Area" is must be installed in a gas/air tight fire proof continuous duct.
In addition, a protected area conveying piped flammable gas is required to be adequately ventilated directly to the outside air by ventilation louvre The duct must be ventilated to atmosphere.
Fire collars would need to be fitted between properties.
In accordance with ADB(4), a pipe carrying flammable gas through a protected area (e.g. a dwelling) must be of screwed steel or of all welded steel construction.
However, a gas pipe is not considered to be within that protected area if that pipe is completely separated from the protected area by fire-resisting construction, such as a ventilated duct.
The fire-resisting properties of that construction need to be as recommended by the relevant guidance document.
Copper pipe with soldered joints may be routed through or in that protected area,provided that it is encased within its own duct/shaft of a similar fire rating for the protected area.
Local Building Control authority will need to be contacted to confirm whether the status of a corridor or space being communicated with is classified as a fire-protected.
In the case of existing gas pipe installations in protected area leaseholders and freeholders would need to inform there buildings insurance provider and make sure they are covered by their policy.
If conversions of buildings are carried out post the date of regulations existed then compliance is mandatory regardless.
Question from a Surveyor;
I have read with interest your article on the internet regarding Gas Pipe Supplies in communal areas and other properties. I am a surveyor working on a refurbishment of a multi-occupancy building where ideally I would like to run gas supply pipework to 2 upper flats horizontally through the basement flat in a ventilated and fire protected duct fixed under the ceiling (the meters are in the front basement area). The pipes would pass to the rear elevation and then run up the back of the building. The heating engineer who is quoting for the work has said that Gas Safe say this arrangement is unacceptable. I have also had the same answer from them and whilst they referred me to BS 6891 and IGEM standards, they haven’t pointed out the exact regulation that prohibits this arrangement. I cannot see how this arrangement differs from a horizontal supply pipe that solely serves the basement occupancy, which Gas Safe say is permissible. Are you able to indicate the actual regulation which governs this issue? Thank you in anticipation of your assistance
Culkin Plumbing and Heating;
The regulations are different regarding gas pipes within the property it is supply, as apposed to a gas pipe passing through one property to supply another. Gas regulation applies as well as Building Regulations Approved Document B (ADB) Fire Safety(4) – England and Wales I don't know which specific regulation(s) comment on this but tend to refer to the guidance IGEM/G/5 as the regulations themselves are based in very legal jargon. http://www.igem.org.uk/media/270556/Pages-from-IGEM-G-5-Edition-2.pdf I've also attached a guidance document which I found helpful. Personally I can't see why you cannot why you couldn't do what you've planned provided your meeting the requirements. Hope this helps.