Sewer

[scantronic]

hi
I was wondering what the pipe in the bottom left corner is for and if any of you could tell me that would be much appreciated

 

[mfarrow]

Unusual to find these things on your roof.

The pipe likely discharges to a vent somewhere, a pipe against the building perhaps. Whether it's needed is dependant on whether you are getting bad smells? Is that the reason for your post?

The sewer is sealed with a water trap, as per the bottom centre. This was to stop smells coming up from the main drain, with the vent taking care of things locally.

 

[scantronic]

Thanks there is the main stench pipe that the toilet connects to but that's in the opposite direction, I believe there was either an air inlet or a vent pipe against the garden wall that has been removed and yes I am getting smells so I would like to reinsert whatever was there

 

[mfarrow]

Reinstatement will not be an issue, but consider alternatives like maybe a better cover.

Also there was an assumption in my last post that the shiny spot at the bottom of the view of the manhole is the knob for a plug? It wasn't clear but is that the case? If so keep it there.

Smells may also be exasperated by the inlet pipes above the invert of the sewer. Do they dropraw sewerage in and splatter it on the walls, especially the light-brown pipe in the top right?

 

[scantronic]

The one at the top right is for a washing machine so not really raw sewage, how would I go about reinstating the vent pipe?

 

[Hugh Jaleak]

It's a common Victorian sewer design, you have an 'Interceptor' trap, which seals off the house drains from the main sewer in the road. The plug in top socket of the outlet is the rodding eye, the stopper is removable to allow rodding of the section of drain from the chamber out to the road.

The pipe in bottom left corner of pic, (top of chamber), would have been connected to a vent (air admittance valve) somewhere nearby at ground level. The idea was, air passing over the top of the stack would cause a negative pressure in the house drains, thus drawing air in via the low level vent, through the pipework and out the stack, thereby ventilating the system. However, the low level vents often stuck open or got damaged, so many were removed. You can try reconnecting it, and using a modern external type AAV and see it this helps with issues. Original would have looked something similar to that in the pictures here: //www.diynot.com/diy/threads/sewer-drain-ventilation-advice-required-please.297016/

Smells though are usually a result of material building up in the system, often a dead giveaway of a blocked interceptor. Yours is clear, are all the other sections of the system flowing ok?

 

[scantronic]

Thanks for the reply I will be buying an aav in the near future, yes the whole system seems clear and flows very well so it's just a case of finding where the original one was and putting a new one in?