What's this toilet vent pipe thing?

[Rhino]

On the outside of the house is a pipe running straight up from underground, through the eave, and out through the top of the roof. Another pipe connects it at a T joint with the toilet. You probably know what I'm talking about.

What's it for? Does it need to be there? It seems to be on all older houses and apparently not on newer ones.

The top of this one above the roof line is all rusted and full of holes. I'm about to get the tile roof fixed up and prep'ed for painting and wondering if I should either remove or replace this pipe first?

When I replace the toilet, does the new toilet need to connect up to it (if it stays)?

Cheers

[Re@der]

This is the terminal vent for the sewer drains. It is placed at the highest point of the underground drains. The purpose is to release all gas into the atmosphere. It is a mandatory part of the sewer drainage system as a build up of gas from rotting organic matter could be very dangerous.

[Ahar]

Sounds like you need a plumber

[Wayne]

On the outside of the house is a pipe running straight up from underground, through the eave, and out through the top of the roof. Another pipe connects it at a T joint with the toilet. You probably know what I'm talking about.

What's it for? Does it need to be there? It seems to be on all older houses and apparently not on newer ones.

The top of this one above the roof line is all rusted and full of holes. I'm about to get the tile roof fixed up and prep'ed for painting and wondering if I should either remove or replace this pipe first?

When I replace the toilet, does the new toilet need to connect up to it (if it stays)?

Cheers

newer houses have the vent inside the wall rather than outside so you don't notice as much - they still have a pipe with a vent cap that pops above the roof.

[spurner]

Check with a drainlayer/plumber. There is a good chance that it's unnecessary and can be removed completely. I've removed many toilet vents when doing bathroom renovations. It means greater choice of replacement pans too as you don't need a vented one.

I think in the past they used to vent every toilet(which was a bit excessive), but nowadays you only need to vent the end of the line. Even then, you may be able to reduce the height of it so it doesn't go through the roof.

Obviously you need to speak to someone who knows what they're talking about though.

[Re@der]

This sounds as though it is not a toilet vent but rather the drainage system terminal vent which is necessary. I am pretty rusty on this but the regs used to be if there is another terminal vent close by you may be able to remove. Cant remember the regulations but probably within about 2 meters. A toilet vent is only necessary if it is more than a certain distance away from the terminal vent. The toilet vent comes directly off the pan and as Spurner points out is rarely necessary these days.

[Wayne]

This is not a toilet vent but rather the drainage system terminal vent which is necessary. If there is another terminal vent close by you may be able to remove. Cant remember the regulations but probably within about 2 meters. A toilet vent is only necessary if it is more than a certain distance away from the terminal vent. The toilet vent comes directly off the pan and as Spurner points out is rarely necessary these days.

and the toilet vent is there so that, as the waste runs down the pipe, it doesn't suck all the water from the toilet trap. The terminal vent does the same which is why a toilet vent shouldn't be necessary unless you have a long run from the pan to the main sewer line with the terminal vent.

[eri]

as stated a breather is needed to equalize pressure on stuff going down the pipe and also to prevent sewer gas, odorless, explosive methane, coming up the pipe

the thinking on location has changed over the years but the need is still there

just imagine a tenancy where you gave a no smoking clause, so the tenant goes into the bathroom, lights up and before they can open the window the whole room turns blue for a second and the window and door are blown out

tenant stagers out without eyebrows then calls the fire brigade

http://en.wikipedia.org/wiki/Drain-waste-vent_system

[Wayne]

Check with a drainlayer/plumber. There is a good chance that it's unnecessary and can be removed completely. I've removed many toilet vents when doing bathroom renovations. It means greater choice of replacement pans too as you don't need a vented one.

I think in the past they used to vent every toilet(which was a bit excessive), but nowadays you only need to vent the end of the line. Even then, you may be able to reduce the height of it so it doesn't go through the roof.

Obviously you need to speak to someone who knows what they're talking about though.

yes - either leave alone or get a plumber (and possibly a permit to remove).

[Rhino]

Thanks for all the info, sounds best to repair it above roof line and leave be. Hopefully the replacement toilet won't need to connect directly, but I'll discuss that with a plumber.

[Bluekiwi]

Okay here is another question, and technically I am doing what they call a "Thread Necromancy" by bringing back an old thread, which on some websites is against the rules.

So we have a lot of smells coming out of our vents, and we have a HRV system which somehow seems to suck the smells back from the outflow vent into our house, or else if no wind the smells drop down into our front courtyard giving us nice smells by the front door.

I have a theory that we are at the low point in the sewer system so we may be getting a lot of gas and smell from all the neighbours.
Does that sound feasible ?

We have options to:
A. Cap these vents and see if the smells bubble up from the toilets.
B. Extend the vents so the smells go to a point of the house further away from the entrance / front door.

Any other bright idea's ?

[eri]

don't cap the vents as that could lead to a methane explosion later on

see if you can add some piping to extend them; higher, around the corner, downwind of the HRV intake

[Bluekiwi]

Okay thanks for that, cheers Paul

[Bobsyouruncle]

Or change them to close coupled toilets and remove the vent altogether....

[Wayne]

Or change them to close coupled toilets and remove the vent altogether....

'Close coupled' refers to the cistern connecting directly to the pan rather than have the discharge pipe visible.
Rhino is talking about a terminal vent - have to have them.
Nothing you do to the toilet will remove the need for a terminal vent.