Sewage treatment plant SVP/AAV confusion

[flanagaj]

I have read a number of the posts on here regarding the above, but when I look at the Graf installation instructions, they stipulate that AAV are not suitable.  So if AAV are not suitable, and I want to have internal soil pipes that terminate in the roof space, is the simplest solution to run an external SVP at the house end of the property, and then have AAV on the internal stack pipes?

 

 

[joe90]

Most houses connected to mains drains benefit from neighbours soil vent pipes which of course with a STP this does not happen. With mine I had a toilet in the detached garage and ran a soil vent pipe from that and an AAV in the house. Yes you could run a SVP up the outside of the house before it enters the house or run the SVP out through the roof which will give you a cold bridge but IMO only a small one.

Edited December 30, 2024 by joe90

[Kelvin]

I extended the sewerage line to the garage (shower and loo in there) and took the SVP through the garage roof. I also have an AAV in the house inside the coomb void where I just had enough height to be higher than the sink. We also fitted the percolation pipe as per the bottom picture. I called Graf about that and they recommended that’s the best way to do it. It’s all been fine since we moved in 6 months ago. The main advantages for me were no holes through the roof so no air tightness problems to deal with, cold bridges (albeit small), leaks, damage to the metal roof, and it leaves the roof looking really clean with no pipework. 

[nod]

I’d thought about this on our previous build Being it was the first time I’d fitted a TP and no knowledge of TPS 

Other than gem of info that my architect supplied “Just like a 59 gallon barrel that you stick in the ground and the waste runs through it “ 

I added a vent near the TP 

 

[ProDave]

A TP does need a real vent at both ends of the drain run.  I thought I had covered that by incorporating an outside vent stack on the static caravan at the far end of the run.

 

But BC argued what if the 'van is removed?  I argued that would be the responsibility of whoever disconnected it to make arrangements.  They did not accept that.

 

The only alternative they offered me was run an external vent pipe up the outside of the gable end of the house.  The problem with that the drive had been concreted by then and there was no way I was digging it up.  So reluctantly I took the internal stack pipe up through the roof to a vent. 

[Russell griffiths]

I’ve hidden a svp on the scruffy side of the house, the area that the ASHP sits and the LPG bottles, then another vent near the tank. 
my Graf tank has no noticeable smell at all. 
our other septic tanks stink. 

[crooksey]

You are over complicating this, when you dig the tank in, you will need a control box somewhere (usually hidden) for the compressor etc, so put the vent direct from the tank there. 

Edited yesterday at 15:27 by crooksey