Gas pipe and ventilation

[Lee]

Hi,

Situation is a 1st floor flat which has a (ceramic tiled) suspended wooden floor over concrete, and which has a steel (or iron?) gas pipe running horizontally in the "void" between the concrete floor and the wooden floor.

Question is, it it permissible to seal around the gas pipe where it exits vertically from the floor? My feeling is probably no...but cooking smells and yucky cigarette smoke smells are coming up through this gap from the flat below and sealing it would be an easy way to tackle this problem.

I realize that finding out where the smells are getting into the void in the first place is the proper thing to do, but neither the owner nor freeholder of the other flat is interested - and pursuing it is not likely to get anywhere :(

Lee

[andrewpreece]

I have just a few days ago asked a similar question on this NG regarding the enclosure of a gas pipe in a partition wall. The advice I was given was that pipes can only run vertically in a partition wall ( Why I have no idea, unless it is a matter of convection and ventilation ) and any such pipe needs to be 'enclosed in building material'. For example, , placing the gas pipe behnd plasterboard is OK if dot and dab adhesive is used to form a closed channel around the pipe when the plasterboard is put into position, or wooden battens are used to form a channel for the pipe, then plasterboard applied on top. In other words, there seems to be a requirement to minimise the volume that the pipe is enclosed by, in case a leak occurs. I take it that there must be some form of ventilation to open air for this pipe enclosure otherwise a gas leak would find a way to force itself out of its enclosure into to the partition wall/floor space. I imagine then that the pipe should have a clearance hole around it where it exits a wall/floorspace.

This is all supposition for pipes enclosed in the floor: my old combi gas pipe ( c. 1988 ) was enclosed under the first floor floorboards with no attempt at ventilation.

Andy.

[Paul Barker]

When the pipe was layed it was a normal suspended floor, so as long a rules about notching or drilling joists were observed there were n other requirements. Especially no requirement to ventilate.

Now the floor is tiled you should re-interpret the rules for your ow safety.. Effectively you have a pipe in a horizontal duct. Ducts shoul be ventilated to outside air to ensure that any gas escapes do no become unsafe. Size of vent is dependent on cross sectional area o duct. 0.05 to 7.5 msqrd vent is .05 msqd. duct exceeding 7.5 msqd ven

1/150th of duct area. The gas pipe as it enters from the flat below an as it emerges through your floor is better sealed to provide a 1/2 hou fire stop. Ventilation should be to outside.

There is an environmental health issue vis a vis smells from the fla below reaching your flat. Maybe the two dwellings are not fire stoppe and sound insulated up to current standards. If you are unhappy wit the response from the responsible person for the flat below talk to th environmental health department. Be awar that they will take an interes in as whole load of other things once you let them in.

Personally I would re-run the gas pipe above a tiled floor in tile boxing ventilated to outside

-- Paul Barker

[Paul Barker]

It also occurs to me that there is a fire prevention issue i

ventilating the sub floor between two flats, which may over rule what have said. To that end I would go and talk to your local fire brigad about it and ask them along to advise. This points towards geting tha gas pipe out of there and making a new duct (boxing it in) outside o the space between flats.

Actually I hate gas pipes which are run inside dwellings, for you safety it is always best to run them externally as far as possible

-- Paul Barker

[Lee]

Thanks, lots to think about.

I tend to agree and it may yet come to that anyway, probably use it a good excuse to get the meter relocated outside along with the pipe. There is only one appliance (combi), so it won't be too involved and the meter is taking up useful space.

Lee