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.

"Mr Fizzion" wrote in message
...
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.

In article ,
ne says...
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?

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.

"Rob Morley" wrote in message
t...
In article ,
ne says...
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?

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

Mr Fizzion wrote:

What about gas pipes passing through a plasterboard ceiling and the
floorboards above? Is there a similar requirement for the same reason?

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:


Mr Fizzion wrote:

What about gas pipes passing through a plasterboard ceiling and the
floorboards above? Is there a similar requirement for the same reason?

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.

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?
--
Stuart @ SJW Electrical

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Lurch wrote:

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:


Lurch wrote:

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.

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.

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.

This, I cannot comment on as I don't know for sure but I have never
seen a sleeved gas pipe under a floor.
--
Stuart @ SJW Electrical

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Lurch wrote:

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.

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:


Lurch wrote:

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.

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.

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.
--
Stuart @ SJW Electrical

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