Air admittance valve

[PT1984]

Afternoon all. Is there any reason i cant cut the stinky pipe short just after the 90 and fit an air admittance valve? Even better just take off the 90 bend and put in a push fit AAV? Had one in the loft on our previous, but newer house with no issues.



Having problems with ingress around the chimney and the stinky pipe as it penetrates the roof. The chimney Im going to take a few courses off, cap it (need to research if it still needs ventilating), then get someone in to cut new flashing in.

With the pipe I just want to remove it. New tile, and assure the anti ponding strip / eaves protector is there. Then replace the section of soffit.

It s just a bodge atm. It s had several previous attempts at a repair, mostly just tubes of silicone dispatched everywhere.

FYI as the image is taken the right part of the chimney is where the main waste stack is. The left side is the glue for a gas fire which is no longer used. I just just bunged it with mineral wool to stop the draught.

Edited by PT1984 on Saturday 14th February 13:17

[Baldchap]

It needs to be higher than water will ever be, eg cistern or full bath etc. Beyond that I see no reason why you couldn't move it. They can and do fail though, so below a window wouldn't be my choice.

[finlo]

Also I don't think they would work correctly unless upright.

[bobtail4x4]

and it needs a vent at the highest point of the drain run,

AAV`s are ok in limited places,

[Xcore]

There is risk of them freezing shut during a frost and is generally bad practice not having atleast one vent to atmosphere in a property.

[PT1984]

Thanks all. Can see why they are less hassle in a loft.

[RammyMP]

The top of the pipe needs to be a certain distance from a window as well (to avoid smells), don’t know what the dimension is though.

[RammyMP]

RammyMP said:

The top of the pipe needs to be a certain distance from a window as well (to avoid smells), don t know what the dimension is though.

Google says: Termination Height: Must extend above the roofline. If within 3 metres of an opening (window/door/air brick), it must be at least 900mm higher than that opening.

[bobtail4x4]

from the old 3 foot and 10 foot
900mm and 3000mm

[Little Lofty]

It could be taken out of the roof and swan necked around the soffit, not as neat but solves the leak issue.