Air vent on toilet drain. - Where does it go again?

[bert]

this is my lovely green toilet. if i have to vent the drain can i put an external vent out side? what regs cover this? height etc etc?
anyone know?
the loo is, or will be in a lean to out the back.
not much room inside for an internal vent pipe plus boxing and all that so i hoped i could tidy it all up and put the vent out side..
also guys , d9o i need a valve on this or can it be an open vent?

[Dave_L]

My outside khazi is connected just like this but with no vent whatsoever. Seems to work *erm* quite well.

[lutonlagerlout]

if the run already has a vent pipe then no need for another one, if you do vent it normally has to be 600mm above the roofline,which would be awkward in a single storey outhouse
alternatively you can use a durgo valve seen [url=http://cgi.ebay.co.uk/AIR-ADMITTANCE-VA ... egoryZ5721
2QQcmdZViewItemQQ_trksidZp4340.m263QQ_trkparmsZalgo%3DSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D15%26pmod%3D250709227671%26ps%3D63%26clkid%3D6034020985325241531]here[/url]
check to see if your house has a vent already first mate
LLL

[Tony McC]

Part H of the Building Regs is what you need.

[bert]

part h says i cant use a valve outside, or its not recommended.
the run is already vented to atmosphere , it doesnt matter if the vent isnt at the head of the drain then?
the vent is on a branch about 14 meters down stream on another wc, there are two rain water/household waste water drains in-between.

[lutonlagerlout]

AFAIK the vent is there to stop a build up of methane in the sewer
1 vent is normally enough
LLL

[bert]

so me doing a huge richard 3rd wont cause any negative pressure and pull out all the water from the traps? its not likely is it?

[seanandruby]

Only on a Monday morning if you've had a wild w'kend :laugh:

[lutonlagerlout]

if there is no vent at all this scenario can occur,where water gets sucked out of the traps
if you are in any doubt speak to your local BCO,and be nice to him/her bert
IME in the last 18 years of extensions/refurbs 1 vent is enough
LLL

[bert]

lovely , thanks guys.