New soil pipe into existing drain

suze369

Please forgive this potentially numpty question.

I have a large rear bedroom that I want to divide into a large single room with an upstairs bathroom in the other part. 

I have a normal drain pipe running from the guttering into a drain at the bottom of the rear wall where a toilet would be fitted. The drain is also where the sink and dishwasher water goes to from the kitchen below.

I don't know if I am overcomplicating it in my head as to how complex a job it would be. I have looked online and all the articles I see don't answer such basics! So before I go out and get quotes I wanted to make sure I can fit a soil pipe into that same drain alongside the drain pipe. Otherwise I would leave it for now and keep saving.

Can anyone please advise? 

Jeepers_Creepers

You might, or you might not.

On some houses, the 'surface water' drains are separate from the 'sewage' drains. On others - usually older properties - they are the same.

Where is your existing loo? And, outside this, where is the nearest manhole cover?

suze369

Thanks. 

The existing loo is downstairs about 2.5 metres to the left of this drain position, house is L-shaped so its not in a line with where a bathroom could fit upstairs.

The nearest man hole cover is in neighbours garden.

Do you think my water company could tell me if the drains are separate? 

lesalanos

The downspout is unlikely to be wide enough to be used as a soil pipe 

stuart45

Do the rainwater pipe and kitchen waste pipes go into an open gulley?

NSG666

Can you post a photo of the drain the existing downpipe goes in to?

Ramouth

When you purchased the house you are likely to have had a drainage search carried out.  If so you should have a plan showing the location of drains in the pack of information you received from your solicitor and this will tell you if have combined or separate sewers.

Section62

suze369 said:

I have a normal drain pipe running from the guttering into a drain at the bottom of the rear wall where a toilet would be fitted. The drain is also where the sink and dishwasher water goes to from the kitchen below.

...

So before I go out and get quotes I wanted to make sure I can fit a soil pipe into that same drain alongside the drain pipe. Otherwise I would leave it for now and keep saving.

If it helps shortcut a long conversation... it is 99.99% certain that you won't be able to connect a toilet to an existing rainwater pipe and/or open 'drain'.

You'll need a pipe from the toilet which is at least 100mm in diameter* all the way to an underground connection made with a pipe leading to a 'foul' or 'combined' sewer.  (*not absolutely correct in all situations, but accurate enough in this one)

Also, if you are going to use it, you will need to verify that the pipe connected to the kitchen sink/dishwasher 'drain' is actually connected to a 'foul' or 'combined' sewer.  All too often these are connected to surface water drains, and polluting rivers and watercourses with untreated human waste will result in a knock on the door, sooner or later.

stuart45

One of the problems with underground drainage work is that you don't really know all the potential work involved until it's been dug. If it's an old house the chances are that it will have salt glazed pipes covered in concrete which makes connecting up a lot harder. Modern houses with plastic pipes covered in pea shingle are much easier. 
If it's an older house though it may well have a combined system. Some have still got the 2 pipe system at the rear with the hoppers taking the bath water and rainwater. When I worked for firms as a jobbing bricklayer you would usually find a tennis ball in there causing a blockage.

FreeBear

Section62 said:  You'll need a pipe from the toilet which is at least 100mm in diameter* all the way to an underground connection made with a pipe leading to a 'foul' or 'combined' sewer.  (*not absolutely correct in all situations, but accurate enough in this one)

And any new connection to a foul/combined sewer will require building regulation compliance & sign off. It needs to done right as it is the home owner that is ultimately responsible and is the one who will get prosecuted if the council or water board decide to take action.

Harrywayon

We added a soakway it was so much work had to dig so deep and we had to redo the floor. The water company didn't have plans the builders couldn't find the drains they started ripping of each corner 7ft deep never again