Neighbour using my downpipe

sharon5cc

IMG_1421.jpeg

Apologies for not using the correct terminology. We are in a terraced house and our upstairs bathroom backs onto neighbours. We have a downpipe on the outside that goes into the main drain ( it is a shared main drain). The neighbours waste water pipe from upstairs attaches to our downpipe. Is that normal? Been like it for years but we now keep getting internal drain blockages . I know this could still be our fault but if we are getting their waste too it will never be there fault. Have now added photo. It is 20 years old.Water sometimes bubbles up in downstairs toilet. Southen water say shared main drain not blocked

uknick

Just to clarify, the main 110mm downpipe is getting blocked, not the sewer itself?

Boohoo

https://forums.moneysavingexpert.com/discussion/6657203/neighbour-using-my-downpipe

Do you have any photos so we can know what your on about and give better opinions or advice?

Grumpy_chap

https://forums.moneysavingexpert.com/discussion/6657203/neighbour-using-my-downpipe

Just to clarify, this is a foul water (not roof drainage) downpipe from your bathroom which also takes foul water waste from the bathroom of the next property in the terrace?

Does water flow freely from the downpipe to the sewer?

sharon5cc

photo now added. Water sometimes bubbles up in downstairs toilet. Southen water say shared main drain not blocked

born_again

Are you sure that it is not a shared down pipe? (check deeds)

Boohoo

That's soil pipe.

Do you have a photo of the whole system of pipes on the outside to show please.

If it backs up in your WC have you asked the neighbour(if you get on) if theirs backs up or has issues?

WIAWSNB

Hi Sharon.

A 'downpipe' usually refers to a 3" wide pipe that takes roof rain water from the guttering and down to earth. What you appear to have there is a 'soil vent pipe', used to take toiler waste to the sewer - Nos 1 and 2, shower and basin, etc.

Can you confirm, please?

It is unusual for two properties to share a single vent pipe like this. (Edit - possibly not uncommon in older terraces.)

Could you post a couple more pics, please - you can actually add them straight in to your reply;

Pics to show where the pipe goes above the yellow arrow.

One to show where the blue goes.

One to show how it disappears into the ground - orange.

What the green pipe is - is that the lower toilet that backs-up?

And what's the purple pipe?

Oh, and where is the boundary?

And what - exactly - did Southern Water check and say about this? Did they make any comment about how the two properties shared a single vent pipe?

You say, "It's been like this for years" - what has? And, "It's 20 years old." What is?

uknick

I'd not like to think what came out of a person on the toilet to block that pipe 😀

As it affects the downstairs toilet, are you absolutely sure it's not a blocked drain where it meets the soil pipe? What did Southern Water actually look at?