House p trap?

[DrGonzo]

I have a family member who has property in Spain where code requirements are not exactly strict

The septic tank smells in the house.

There is a section of the plumbing for the main waste pipe that comes from the house and runs a150ft +(slight angle from horizontal) before running down 20ft into the septic tank.

There is either a problem with the venting at the top of the house - the pipe does not extend beyond the roof but rather into a little roof cap or some other issue with an open pipe in the wall cavities.

No-one knows if there is an open pipe in the house (in the concrete cavities) or some other problem but when the central ventilation/AC is turned on, septic tank smell comes out of the AC vents. You can also see a vent installed near the tank in the picture below which doesn't seem correct - this is an outside open to air room but the vent should clearly not be there!

To try and improve this, they added a vent in the main waste pipe and knocked a hole in the wall of the house underneath one of the toilets!
I can only assume this was a way to increase the ventilation of the tank but it has made no difference.

Can you add a p trap in a long section of 125mm pipe or will this cause back up problems?

 

[Hugh Jaleak]

I don't see why you cant fit a trap, although make sure it is easily accessible for cleaning out when required. A lot of UK drainage still incorporates 'interceptor' traps, which are unfortunately rather prone to blocking.

 

[DrGonzo]

I don't see why you cant fit a trap, although make sure it is easily accessible for cleaning out when required. A lot of UK drainage still incorporates 'interceptor' traps, which are unfortunately rather prone to blocking.

Would a wye 90 degree be too extreme for the entrance and exit?
There are some 67 degree wyes to allow clean out access but my maths is not up to scratch to make that work.
I assume to cut that in I have to use flexible couplers, there's no way to make the pipe fit in with cement weld?

Also it seems to be 125mm grey waste pipe and I can only find 110mm in the shops.

 

[Hugh Jaleak]

125mm is a Spanish size, you'll only find 110mm and 160mm over here. That stuff you'll have to look online for I'd think. I wouldn't use 90's, couple of 45's and a 90 maybe underneath between the 2 45's.

 

[DrGonzo]

125mm is a Spanish size, you'll only find 110mm and 160mm over here. That stuff you'll have to look online for I'd think. I wouldn't use 90's, couple of 45's and a 90 maybe underneath between the 2 45's.

To allow a cleanout is there a wye that I can install?
Problem is the inlet would be horizontal so what tee or wye would work with a 45 degree?