Hiding a gas pipe

[craigtdann]

Hi,

I intend to put an Vaillant 838 in my loft (as a side topic any views on the 838 would be appreciated). I have done the calcs and have determined it will require the fitting of a new gas feed up the outside of the house.

I just wondered if it was possible to hide the gas pipe within a 40mm waste pipe so it matches the other pipes running up the house. One plumber have advised me it's possible, but I'd like to get a second opinion from the experts on this board.

Any advice welcome.

Thanks

 

[craigtdann]

When I say possible I mean legal! Thanks

 

[landyandy]

What size is the gas pipe that you have calculated it to need

 

[Nige F]

Think you`ll find it`ll need to be painted yellow - with a black band at the end near where it goes through the wall to the boiler - make sure it`s not upright - use some old iron spiked hooks to hold it to the wall - and remove half a brick where it goes through - so that everyone Knows it`s a gas fitter`s done it

 

[Biggles..]

Yes it's possible,just keep the ends open.

You should just about get 35mm copper inside a black 40mm solvent waste.can't expect your size will need to be more than 28mm so 32mm waste will do it.

 

[Biggles..]

Think you`ll find it`ll need to be painted yellow - with a black band at the end near where it goes through the wall to the boiler - make sure it`s not upright - use some old iron spiked hooks to hold it to the wall - and remove half a brick where it goes through - so that everyone Knows it`s a gas fitter`s done it

Think you'll find gas pipes only need to be identified in commercial
Installations.

 

[craigtdann]

it's a 22mm pipe

thanks for all the responses so far!

 

[landyandy]

it's a 22mm pipe

You have almost certainly got your calculation wrong.

Andy.

 

[craigtdann]

in what way? two big or too small?

I calculated I require 3.55 m3/h extending my existing 22mm run (including elbows and bends would give me an effective run of 13.5m. I calculate this to give a 0.9mbar drop. With a large (5 ring burner) hob also on the run I cannot use this route - so I have to run up the wall.

Does that make sense or have a made an error.

I'm not sure how you can say it's wrong without knowing the effective pipe length? Thanks for the help though....

 

[kirkgas]

how are you going to secure the gas pipe every 2.5m if it is inside a plastic pipe, why are you covering it, for looks or protection? if for protection you would be better fitting steel,

 

[craigtdann]

Just for looks.

If securing the pipe every 2.5 is a requirement then I cannot do it.

I will secure the waste pipe every 1-1.5m, but I appreciate this is not the same as securing the gas pipe.

Are you saying I cannot do it then?

 

[JPC]

calculations apart, you can cut the wastepipe along its length...cut out/drill (before cutting it would be easier) for the clips that support the gas pipe, and snap it over the top ?

that way its vented and your house looks... errrrrr... better ?

 

[craigtdann]

thanks - that's a good idea. I could line up the waste pipe clips with the gas clips.

If I do that I can also fit the waste pipe afterwards if I don't like the look of the gas pipe.

Thanks all - still intrigued as to why my calcs are wrong, but at least I know I can cover it now.

Cheers - Craig.

 

[landyandy]

I calculated I require 3.55 m3/h

Just double check this.

Is it the 838 you are looking at

Need to know a bit more regarding your pipework.Have you got 22mm from your meter

Andy.

 

[craigtdann]

Yes - it's the 838.

I calculated it as :- Kw/CV = litres/sec
litres/sec *3.6 = m3/hr

i.e 38/38.5 (assuming 6m3/h supply) * 3.6 = 3.55m3/hr

The pipework is 22mm at the meter - it travels along the outside wall for 1m and then elbows in to the house - it runs behind the kitchen cupboards to a downstairs toilet (approx 4m) where it is elbowed upwards next to the soil stack to the first floor. I will need to extend this to the loft giving a total vertical distance of approx 4-5 meters. I then plan to mount the boiler on the same wall that the gas enters - so I need to go back another 4m + a couple of elbows. All in all this totals approximately 13.5 meters

Have I made an error?

Thanks for the help