Aav

[townfanjon]

Morning chaps, just a quick question, just up at my sisters and shes having an extension built, internal soil stack that used to vent through the roof, builders starting to roof on monday and has done away with the soil pipe through the roof, he has just put an aav into the top of the branch leading to the toilet, in other words its about 300/400mm of the floor. Am i right in thinking there is a specific height ?

Thanks in advance

 

[snowhead]

Above highest flood level of anything connected to it.
So if was a WC only, then around 450mm, or if a hand basin around 800mm

 

[joni os]

Sewer should be open vented at end of longest run. If shared sewer with neighbours then BC might be satisfied by their vent. Check with Building Control.

 

[SimonG]

1 in 6 to be open vented rings a bell.

 

[townfanjon]

Yep its slowly coming back lol, builders just put it on without much thought, its dormer semi, so i am guessing they have separate connections into the sewer.
Many thanks for your replies chaps

 

[plumben]

Yeah every 1 in 6 needs to have open vent
And AAV needs to be higher than the highest spill over level
Also needs to have a air supply, vented area