Hi Julian. Not going to stick my neck out on this one but here is Part H. http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADH_2002.pdf Page 10 seems to suggest that stub stacks are okay in some situations. I have been certainly been allowed by Building Control to fit durgos in en-suite bathrooms but it is always possible that they were relaxing the requirement - but I don't see anything in the doc which says that every stack must be vented to the outside. I would ask him [nicely] which paragraph of Partg H he is enforcing.

AAV are one way devices. I thought stacks were to let sever gas out as well as in.

The normal rule seems to be that your furthest stack from the main must be open but nearer stacks can have AAV.

"The normal rule seems to be that your furthest stack from the main must be open but nearer stacks can have AAV. "

Cwatters has got it right according to my NVQ2-3 plumbing/heating book,I was looking at it the other day regarding a similiar question

Posted By: tony
if a main drain becomes blacked everyone gets glugging and smells.

more likely brown than black

I am working on a house with a private septic tank (unvented) in Scotland & was planning to vent the soil pipe at the head of the run only and use AAV's else where (2 other vertical stacks in the same building) to minimise the number of penetrations in the roof (there are lots of rooflights and don't want lots of separate stacks sticking up thro' the roof)

The pipe at the head of the run only has a gnd. fl wc/sink/bath on it and the next one down the run has an upstairs wc/sink/shower and a wm downstairs - will this be ok?
Does the Soil vent pipe need to terminate higher than the highest appliance in the whole house system (i.e. somewhere above the first floor) or just the highest appliance connected to it?
Does anyone know about venting the soil pipe horizontally through a gable wall (say at first floor level so well away from the ground/people) or does it have to go all the way up and vent above the roof line somewhere? (I am aware of the 900mm higher than the top of any opening within 3m, which in my case would put the top of it 900mm above the ridge line...)

Hi, I have a velux rooflight either side of the ridge as high up the roof as they will go as there are bedrooms in the roof-space. The actual roof build up has no ventilation within it as we have a tyvek BM and there is ventilation above the insulation under the rainscreen cladding (there is timber rainscreen cladding on both the roof and the walls) so using something like a tile vent is out as we have no tiles!! sadly BC up here (highlands) are down to 2 consultants who cover a vast geographical area (1 in the office doing ALL paperwork, 1 doing ALL site visits) so they are swamped! Getting even a relatively quick answer is not an option!... I would really like to terminate the SVP horizontally out of the gable but the only terminals I can find are clearly for a) tiled roofs, or b) vertical termination

Yeah, I did think about something like the option you show from www.aquafax.co.uk as that is what is happening with the ventilation duct from the bathrm & utility extracts - we were going to put these

http://www.screwfix.com/prods/11066/Heating-Cooling/Ducting/Universal-Vent-Brown

on the end of the duct behind the open rainscreen cladding as it is a well ventilated space and that means they are concealed from view externally...

I wasn't sure if something different was actually required for svp's or whether it's just a matter of previous convention! (i.e. most houses don't have rainscreen cladding on the roof!) Prob. should try and check with BC first so we can press on with the cladding but hopefully that will be fine! Thanks for the advice!

that is the English regs but yes, I think you are correct. Only problem with that for us is the unvented septic tank means that at least one stack needs to provide the ventilation and there are a lot of rooflights so the svp will need to project quite high above the roof line - not pretty!