I know that gas pipes passing through cavity walls need to be sleeved and sealed to the sleeving to prevent gas escaping into the cavity in the event of a leak.
What about gas pipes passing through a plasterboard ceiling and the floorboards above? Is there a similar requirement for the same reason?
Are there any specifications as to what the sleeving material should be? The pipe will be 28mm copper, so will 32mm waste pipe be OK?
TIA
Mr F.
I don't know the answer, but can imagine it will be complicated by the probable existence of another regulation to prevent fire penetrating a ceiling via a hole. That is why I am wondering whether you can use plastic sleeving.
Andy.
I imagine that particular attention is paid to cavity walls because even a fairly small explosion there could cause a house to collapse. If a similar explosion occurred in the space under an upper floor it would probably only bring down the ceiling below.
Very true, nevertheless there have been conversations on this group regarding gas passing through stud walling, and I imagine a search back through the uk.d-i-y archives on Google Groups would repay the effort. My recollection was that the advice was to sleeve, I cannot remember what regs if any were quoted, but I think there may be regs calling for this. A sleeve would not be terribly difficult, you could vent it at the upstairs end. FWIW my house has old gas pipes running boxed in in wooden t&g and under the upstairs floorboards, so many many houses must have gas running in unvented spaces, but this may not meet current standards.
Andy
I was waiting in the hope of a reply from someone who is Corgi registered. IMHO it needs to be sleeved, to prevent the accumulation of gas, from an otherwise insignificant leak, in an unvented floor void. One end would be left open to allow gas into a room, where it could be smelt before it reached a hazardous concentration. The other end is sealed with flexible mastic & packing. The sleeve should be the same material as the pipe. With large pipes (drains) you can get intumescent collars to preserve the fire integrity of the structure.
All pipes passing through walls should be sleeved. It is to allow the structure to move/settle without stressing the pipes.
On 27 Sep 2005 01:14:34 -0700, "Aidan" scrawled:
IANARCGI, but I don't think it does need sleeving. How many gas pipes under floors do you see sleeved for their entire length then vented into a room?
Very true. I'd think most such stuff was pre-corgi when a gas fire in upstairs rooms was commonplace. I'd think the current regulations would be that such an installation would require the floor cavity to be ventilated.
If there were no joints within the thickness of the floor, there would be a miniscule risk of a leak. I still think that legally you should sleeve it, there is a forseeable and avoidable risk of a leak into the unventilated floor void. Running gas pipes in an unventilated void is verboten.
On 27 Sep 2005 04:37:11 -0700, "Aidan" scrawled:
What have upstairs gas fires got to do with it? Gas pipes are run under floors in new installations to feed boilers and fires located downstairs as they aren't put under concrete floors.
This, I cannot comment on as I don't know for sure but I have never seen a sleeved gas pipe under a floor.
With suspended timber floors, the floor void is usually cross ventilated with air bricks on the ground floor. The main purpose is to evaporate any water from the ground, but there's no problem installing gas pipes in such a ventilated floor void.
On upper floors, the floor void is not usually ventilated. You are not now allowed to install gas pipes in or through an unventilated cavity. That is what upstairs gas fires have to do with it.
On 27 Sep 2005 08:48:45 -0700, "Aidan" scrawled:
What I meant was, in new installations all gas pipes are run under the
1st floor then dropped down to ground floor situated appliances so it has nothing to do specifically with upstairs appliances. I haven't seen a house built in the last 10 odd years that hasn't had its gas services run in in this way.HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.