Toilet vent pipe missing?

[kasser]

I thought a toilet always needed a vent pipe?
I've just come across a ground floor toilet in a residential property where the waste pipe disappears into the ground and there's no soil stack around, except that of the neighbour on the other side of the party wall!

 

[Chriswareham]

the ground floor toilet goes directey to the main drain

 

[kasser]

But why would it not need venting as opposed to a first floor toilet?

 

[turnpin]

Sometimes if the manhole is shared the manhole is vented via the same stack that enters from the other properties.....regards Turnpin🙂

 

[Chriswareham]

first floor toilet will cause more suction as it goes down the soil pipe if there is on vent pipe it will suck out the water from the traps
a toliet at ground level doesn;t have this

 

[kasser]

OK, makes more sense now. What's the standard reg then for ground floor toilets? No vent pipe if shared manhole? Or is having one always a good idea?

 

[Chriswareham]

some manhole have a vent if there is no vent from a stack pipe so that it flows down the drainage

 

[oz-plumber]

OK, makes more sense now. What's the standard reg then for ground floor toilets? No vent pipe if shared manhole? Or is having one always a good idea?

The regs would state when a vent is required and when a vent is not required.

- Does the drain from the WC enter a vented drain.
- Does the length of the branch to the WC, off the vented drain, fall into the length allowable by unvented branch drains.
- Does the drain to the WC pick up any other fixtures.

There is no specific reg that covers ground floor toilets.
The regs state what is deemed a vented drain, what is deemed a vented branch drain, the maximum allowable distance a type of fixture can be installed into an unvented branch drain with out a vent.
So each case has to be cross referenced with the regulations to see what is or isn't required for venting purposes