Kitchen drain

bouicca21

I want to redo my kitchen. If it is possible I would like to move the sink from its existing position on the side wall to the front wall. The move would be along two sides of a right angled triangle roughly 180cm x 110cm, with a straight line between the old and new positions forming a hypotenuse of about 211cm.

I think the sink empties into a buried drain that runs alongside the side wall, and which is probably clay/ceramic (1960s vintage). Is it possible to make a new connection into such a drain? Would it need building regs sign off? And since this is a ground floor flat, leased to me, would it need permission from the freeholder? My demise ends with the side wall in question, so the drain is under land belonging to the freeholder and serves not only my flat but the flats above me.

WIAWSNB

Although not ideal, it is possible to route the waste pipe internally along the wall, and locate it behind the units. It'll need the required fall, and you should arrange to have access/inspection points at suitable places, say behind a wee panel at the back of a couple of units.

I'm just saying it's possible - I am not recommending it. The runs appear to be short, tho', so almost certainly it'll work without any issues.

To add to the existing external drain is the 'correct' way, but you will need permission, and it will cost bigly.

If you could provide a sketch of the existing and proposed layouts, it would help.

bouicca21

Thank you. The various designers are telling me it is possible, but they, after all, are really just salesmen who can use a CAD programme. I’m worried about being bamboozled into something that turns out to be an open ended money pit.

Here is a sketch (not to scale!). It indicates where the existing appliances and sink are, with the pink line showing where I would like them to be.

WIAWSNB

Ok, so you have a boxed-in vertical soil pipe in the corner of the kitchen, and that is where the existing sink, DW and WM plumb in to?

Q - where are the DW and WM going afterwards?

Q - at what height do the waste pipes feed in to that stack?

And chance of photos to show as much as you can - the stack, waste pipes, etc?

And, what is the length of that existing sink wall? And how far along the other wall will the new sink go?

bouicca21

Here are photos of the area under the sink. The grey plastic pipe connects the dishwasher to the sink’s waste pipe which goes down and then has a right angled turn towards the vertical drain/soil pipe. The (side) wall with the sink is roughly 330cm, with the sink in the middle.

If it is feasible I’d like to put the sink on the centre of the front wall - about 110cm from the side wall.

The pipe that goes through the wall is to an outside tap. I can’t see where the washer drains to as it’s behind the units but logically it is likely it either connects to that plastic waste pipe or connects straight into the vertical drain/soil pipe.

I think it’s an amateur job not just because it looks messy but because when I first moved in there was no u trap!

bjorn_toby_wilde

https://forums.moneysavingexpert.com/discussion/6669786/kitchen-drain

You shouldn’t have too much trouble getting the right amount of fall because the new pipe could be connected lower down the stack with a strap on boss, but you may be on the edge of what you can get away with in terms of distance from the sink waste to the soil pipe. 3m is what I believe is required for 40mm pipe in building regs.

WIAWSNB

Can it be done? Yes.

'Fall' won't be an issue, as I understand it's only around 25mm per metre.

The total run length is pushing it a bit, tho', so you may need to go up in size a tad to ~50mm, especially if it's also going to handle a WM.

In short, you 'may' need to add an air admittance valve, and you really should allow for easy access to check and 'rodding' points in case of blockages.

bouicca21

Thank you so much, that’s really useful. I very much appreciate your willingness to share time and expertise.