Long sink waste pipe run


21 Oct 2015
Reaction score
United Kingdom

I'm slowly renovating an old cottage in the UK and want to switch the lounge into kitchen, and vice versa.

I want to place the sink, and a dishwasher next to it, as shown on the image attached.

My problem is getting the waste water away over a long distance with inconvenient doors in the way. The drain is outside a window where I have removed a sink.

The larger room (the new lounge) is a solid floor with underfloor heating. Luckily, where I intend to cut into the floor and route any pipes there are no UFH pipes because originally that corner was going to be the kitchen area.

I have looked into Saniflo (the Sanivite). It seems to need the pipe to go vertical then fall towards the drain, but I don't want waste pipes all over the walls. The product info says I can't go horizontal and then climb vertically at the end to get out of the wall and into the drain. Also it's not rated for boiling water, so draining vegetables (an important part of a kitchen sink's use, surely?) would appear to be impossible.

At the moment, the only way I can see to do this is to either go vertically up with a pump and then fall (looking very bad) along the walls to the outside by the window, or somehow go down vertically from the sink in order to clear under the doorway, continue at the right gradient all along the walls and then dig down to connect into the drain.

But I've read that the maximum distance from sink to drain with a 50mm pipe is 4 metres. The distance from sink to drain along straight pipes (picked out in red) is 9 metres.

Any ideas?


Sponsored Links
Find out where the external run drains are and possibly go out through the wall to pick up a foul run
To the left of the picture is the road and pavement.

To the bottom is an adjoining house.

The walls are half a metre thick stone.

The only drain I have access to is the one I have put on the picture.
Could that internal doorway be moved to where the proposed sink position is? Swap them around. Looking at that plan, you've too long a run and with too many bends in it that will be buried. When, (not if), it bungs up you are going to be faced with am monumental job to clean it out.

The other alternatives would be to either run a 110mm drain under the floor to the proposed sink position, or the Sanivite, but these are noisy and temperamental. Also bear in mind the discharge pipework must be run as per the manufacturers instructions, otherwise it wont work properly, and will invalidate the guarantee before you even start.
Sponsored Links

I've only just moved the door between the rooms to its present location. It's within a very old cob and lath wall that I have repaired traditionally and it was a lot of work!

Also, the floor was only put down 2 months ago in (expensive) limecrete with UFH so digging it up again isn't an option. However, I could dig into the edge where I've marked in red as there's no UFH there. There is actually a soil pipe to ventilate the left hand room running from near the door to the window but it doesn't run downhill, so I couldn't run a waste pipe through it.

It's my own fault for changing my mind about the rooms, but I'm sure there must be a decent solution. I've been so exhausted and busy trying to get the house ready to take the lime plaster before the frosts arrived that I barely had time to think.

It may be that I need to put the sink between the door and the fireplace (the black and white thing at an angle), which isn't ideal, but it would at least make it easier to put the waste pipe run in.

The other option would be to use the sanivite pump to go up from the sink, through the ceiling and then at a shallow run along the landing above and out under a window and down into the drain.

Of course, I'm assuming digging into the drain in the road would be utterly madly expensive?

Of course, I'm assuming digging into the drain in the road would be utterly madly expensive?
about a decade ago I was quoted £6k to do a direct connection from my house to the nearby road ( because the drains went along the back of 10 houses and then into a road- and were always blocking ) Then the water co.s adopted the drains (y) and I moved.
Digging up the road is best avoided unless there's absolutely no other option, due to cost. (Often when an infill development of 1 or 2 houses are built, the developer looks to try and couple into the neighbouring property's drains, rather than a new connection into the road, purely for cost saving.)

Think your looking at either moving the sink position or the Sanivite TBH.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local