Air admitance valve

[fletchermills]

I'm having a loft conversion done, and the present vent stack pipe has to go/move. The builder has suggested an air admitance valve instead of making a new hole in the roof.

Can anyone tell me if these valves give any problems, do they work correctly, ie let air in, keep smells from getting out, do they need much maintenance, and are there good makes you would recomend buying.

If they are not recommended I can have a stack going up through the roof, but it would have to go in the corner of my new room - would prefer not to that.

Regards

Colin

 

[fletchermills]

oops, forgot to ask, how high does the valve have to be above the highest connection to the stack.

Thanks

 

[Bahco]

I had a loft conversion done last year to my bungalow and the BCO would not allow a Durgo valve
Not 100% but I think you can only use Durgo on a sub stack.
The soil pipe had to terminate 900 mm above the top of the window level or be run 3 metres away from any window.
Suggest you ask BCO for advice.