Draining slightly upwards

[Pete Verdon]

Hi,

I'm looking to move my washing machine to the other end of the kitchen, and hence away from the existing plumbing. I'm fairly happy with extending the inlet side, but I'm less sure about the waste. Ideally, I would have arranged it with a constant shallow slope, starting a couple of feet off the floor and joining into the sink waste just above the floor at the other end. I intended to do this behind the kitchen units, but I've just discovered that although the backs of the units are several inches from the wall, the edges of each unit butt right up against it and would block such a pipe.

So, my question is whether it would be ok to have a pipe that basically lies on the floor for most of its length, rising at one end for the washing machine and at the other to meet the existing waste pipe.

Obviously such a pipe would always have water sitting in it, which doesn't sound ideal. But then again, so does the U-bend under every sink, so perhaps it's ok?

Thanks for any advice, on the waste pipe in particular but also any other tips for this kind of job.

Pete

[Steve]

The bit behind the units is there for this purpose. Just cut out where the pipe goes along the wall and then you can have your fall and pipes concealed neatly behind the units.

Or am I missing something?

Steve

[Pete Verdon]

Well, I had been trying to avoid removing the existing units and worktop, which are a bit of a bodge. It's sturdy enough in situ, and looks reasonable, but I don't fancy trying to take it apart, as I don't think it's been built as designed - lots of odd screws and pieces of wood added all over the place. The guy who used to live here had far more faith in his DIY abilities than he should have.

Maybe I will just have to bite the bullet and do that, though.

Pete

[Dave Liquorice]

That would be the best approach, having a long length of pipe full of washing machine waste water is asking for the "filler" that makes up most of washing powders bulk settle out and block the pipe... Even if you use a liquid washing agent there is still quite a bit of fluff, skin, etc going out with the waste water to do a similar thing.

[Heliotrope Smith]

No problem letting the outlet trail along the floor for a few yards, just make sure that if it goes into a spigot at the sink trap that the pipe is higher than the spigot at some point. Clipping the outlet to the underside of the worktop would usually achieve this. If the outlet goes into standpipe under the sink then again make sure that it is as high as you can make it under the worktop.

[Owain]

I would try drilling the holes in situ (making sure there are no cables behind - mirror on a stick may be handy).

A small power drill with a right-angle adapter might be handy.

Owain

[Pete Verdon]

Thanks. I think I'm going to end up with a hybrid of the two approaches. I'll be using rigid waste pipe, but I'm not going to take the kitchen apart to mount it all to the wall in the correct manner. What I have in mind will end up with most of it sloped downwards to some extent, though

- Dave's point about all the crap floating about in washing machine waste water is compelling!

Pete

[Heliotrope Smith]

If you are going to use riged waste from the washing machine to the waste then it must slope downwards ALL the way to the final outlet. If you use flexible washing machine outlet pipe then if you do not raise it above the machine outlet from the machine on the way to the final outlet then there would be no more water laying in the pipe than if the machine was next to the sink outlet. After all if the machine was adjacent to the waste then the flexi pipe would be sitting on the floor whilst the outlet would be running into the trap spigot or standpipe.

[John Rumm]

and a hole saw since you need clearance for a 40mm+ pipe. You may have to cut the waste pipe into sections and rejoin to get the pipe in.

[adder1969]

On Sep 30, 11:07 pm, "Heliotrope Smith"

Does one also need to loop the waste up then down from the washing machine so that even though water might sit in the pipe is it's syphoned a little from the pump??

[Heliotrope Smith]

No. It would make no difference.

[Pete Verdon]

There's no way I can reach down this space to cut the partitions in the middle of it. What I intend to do is

- Move the end unit out of the way, since it's not so firmly attached (need to do this anyway to get the machine into position)

- Cut the next partition along, since I can now reach it

- Have the pipe pass under the next partition, as high as possible ie touching the bottom of it

- Come out under the other end partition slightly lower so as to maintain a slight slope, but high enough to still connect to the waste.

It's going to be a bodge, but it's going to a) be out of sight and b) work, at least for the forseeable future, so I'm not too bothered.

Pete

[John]

I had a similar problem with my dishwasher. I started with the pipe high - just below worktop height and sloped it down behind the drawers - to a right angle and then into a trap. The hose from the dishwasher is pushed into the sloping pipe without any attempt to seal it as this would encourage siphoning. In 10 years and 2 machines I haven't had a problem although I know it is not ideal.