Horizontal vent pipe

[duffsparky]

Hi All,

This links to a previous topic, go here. Anyway whilst discussing the previous topic I realise that the vent pipe from my HW cylinder may not be correct due to one off the replies pointing out that the vent pipe should rise away from the cyclinder.

Below is a drawing of my system which shows an approx 5.5 metre horizontal run in the vent pipe. This was done several years ago when the cold water storage tank was replaced and put down one end of the loft instead of in the middle of it. The tank was also raised to provide a better shower pressure to the first floor.

Is this horizontal section of vent pipe a problem, all the pipes are well lagged, the loft is fully insulated and boarded except below the main pipe runs and beneath the plinth that the new CW tank sits on.

 

[duffsparky]

The drawing above is wrong it should be the one below.
Appologies for the error
Thanks

 

[clarky101]

Have you put a sprit level on said pipe in roof ?

 

[duffsparky]

Have you put a sprit level on said pipe in roof ?

No, but they all sit running across the top of the joist

 

[PlumbBobBob]

they should have a rise on them really

 

[clarky101]

Have you got a problem or just picked up on something someone has said ? as long as theres a turn in the bubble on your level then no prob....

 

[duffsparky]

Have you got a problem or just picked up on something someone has said ? as long as theres a turn in the bubble on your level then no prob....

I don't know if there is a problem, it's just something I've picked up on because of a comment made in the other topic I started click here.

May seem a dumb question but what is a turn in the bubble on my spirit level?

 

[clarky101]

So its rising up to the cold water tank...just needs a slight rise...

 

[duffsparky]

So its rising up to the cold water tank...just needs a slight rise...

As the pipe is laid across the top of 6 or 7 joists at 600mm centres, I'd imagine it's pretty level although I can see the first 500mm from the 90 degree bend where the pipe enters the loft and turns from vertical to horizontal, slopes the wrong way eg 15mm in 500mm.

Cheers

 

[Mike Jackson]

That's not ideal but as it's 22mm pipe there will still be a slight rise within the pipe. The biggest issues are caused when the vent pipe leaves the top of the cylinder and immediately drops 4 to 6 inches.

 

[Gray0689]

The vent pipe in your drawing is fine running level don't worry about it

 

[ecowarm]

I agree, its fine