Soil Pipe

[dunny]

Morning all,

I would like to replace a soil stack that goes up past the gutter (its a bungalow) with a short stack of about 1m high. I understand that this can be done with a special type of capping but could somebody please advise what would be needed.

Is this approach acceptable from a buildimg regualtions point of view?

Thanks

D

 

[dilalio]

The capping you are referring to is an AAV (air admittance valve) and it only allows air in to the stack. Except for certain circumstances, you need an SVP (soil vent pipe) that allows air to also be breathed "out" of the stack and drainage network for your property.

 

[Hugh Jaleak]

Replace like for like, it's got an open vent for a reason. Fitting an AAV instead may contravene Building Regs and may cause you others issues with positive pressure blowbacks inside the property.

Had several instances when out drain cleaning, whereby toilets have been 'blown' following unauthorised alterations to vent stacks on properties.

 

[dilalio]

whereby toilets have been 'blown'

And that's the pleasant term for it

 

[Hugh Jaleak]

Redecorating in a nice shade of brown....

 

[dunny]

Thanks for the advice. The problem is it is right next to the front door and looks odd. I can't move it because there is a window in the way.

D

 

[denso13]

I can't move it

Do you have any other soil vent pipes around the property or is this the only one?

 

[dunny]

This is the only one.

 

[denso13]

This is the only one.

Better not to fit an AAV then as advised.

 

[Hugh Jaleak]

You can reduce to 82mm plastic if that looks tidier. I suspect if you remove it and replace with an AAV, you'll be back on here within a few weeks complaining about a smell in the bathroom.

 

[securespark]

What smell would that be, HJ?

 

[Hugh Jaleak]

Drain odours. Open stack will vent any positive pressure out the drains. Capping it with an AAV wont, so any back pressure looks for the easiest way out, usually through a bath or shower trap.

 

[dunny]

You can reduce to 82mm plastic if that looks tidier. I suspect if you remove it and replace with an AAV, you'll be back on here within a few weeks complaining about a smell in the bathroom.

Thanks for the advice.