UK Moving Pipes Undersink for Dishwasher

[gjw123]

Does your chosen dishwasher have a service void at the bottom across the rear? Some do, some don't.
Just wondered if by chance your waste pipe eventually descends to floor level, whether you could run it low down?

I'm unsure about this, as I haven't bought it yet unless I can ensure it fits!

So, you're saying that with some models, there might be a void in the rear of the dishwasher low down that the white waste pipes I want to be shallower could potentially fit into, without the need to do much other than make them lower?

Having looked at a diagram, it does appear to have a void low down on the rear (picture attached). However, I think this would be lower than where it eventually goes out the wall. Therefore, I am assuming that this wouldn't work, as presumably (I am guessing) you would want the pipes running in a general downwards direction from the sink to their final destination, whilst this would be lower than where it goes into the wall?

 

[Basher]

So, you're saying that with some models, there might be a void in the rear of the dishwasher low down that the white waste pipes I want to be shallower could potentially fit into, without the need to do much other than make them lower?

Yes, the bottom back of the machine is recessed a little, much like the front is for the plinth. I guess primarily for the water and waste pipes from the machine, but you could have your 4cm there?
But if you can't get the far end of the waste down to floor level, with enough fall, this is a non-starter!
Example:

 

[gjw123]

Yes, the bottom back of the machine is recessed a little, much like the front is for the plinth. I guess primarily for the water and waste pipes from the machine, but you could have your 4cm there?
But if you can't get the far end of the waste down to floor level, with enough fall, this is a non-starter!
Example:
View attachment 94291

Perfect, thanks for this.

Having looked at a diagram, it does appear to have a void low down on the rear (picture attached). However, I think this would be lower than where it eventually goes out the wall. Therefore, I am assuming that this wouldn't work, as presumably (I am guessing) you would want the pipes running in a general downwards direction from the sink to their final destination, whilst this would be lower than where it goes into the wall?

Also, do you have any views on what the wooden beam actually does at the back and whether I could cut into this a bit?

 

[Basher]

Perfect, thanks for this.

Having looked at a diagram, it does appear to have a void low down on the rear (picture attached). However, I think this would be lower than where it eventually goes out the wall. Therefore, I am assuming that this wouldn't work, as presumably (I am guessing) you would want the pipes running in a general downwards direction from the sink to their final destination,

Correct

Also, do you have any views on what the wooden beam actually does at the back and whether I could cut into this a bit?

You would need to establish it's not a vital load bearing support for something above, which might involve some investigation. Don't cut it without knowing why it's there!
Could you establish if it's just part of studwork supporting the kitchen wall (eg plasterboard). Does that beam carry on up above the cabinets - can you see it?
It does look as if you could gain your 4cm without having to cut very much into it, as long as you didn't have to accommodate that solvent pipe joint as well!

 

[gjw123]

Correct

You would need to establish it's not a vital load bearing support for something above, which might involve some investigation. Don't cut it without knowing why it's there!
Could you establish if it's just part of studwork supporting the kitchen wall (eg plasterboard). Does that beam carry on up above the cabinets - can you see it?
It does look as if you could gain your 4cm without having to cut very much into it, as long as you didn't have to accommodate that solvent pipe joint as well!

Thanks again for the reply. I've had a plumber come over to estimate the cost if I feel this is not something I'm able to do.

They've suggested that they could push it back with two well-angled 45's, or perhaps one 45 and one conversion bend 45 (but which apparently had less angle wiggle room). They said they don't think they'd even need to go into the wood and that it would clear the copper pipe.

In terms of considering whether to do this myself or not, would the two 45's be the ones in the picture attached - and if so, how would they attach together as the ends appear to be the same size?

They've also said I'd probably want 2 X new traps (one with a spigot), as well as a dishwasher T-joint on the copper pipe (picture attached).

 

[Basher]

In terms of considering whether to do this myself or not, would the two 45's be the ones in the picture attached

Possibly, but can't confirm that's what your plumber was thinking. That sort of thing perhaps with the first elbow mostly in the left hand cupboard, but there's a coupling where you might want to put it, so the existing T etc will probably be scrapped and re-done to suit the offset required.

and if so, how would they attach together as the ends appear to be the same size?

With a short piece of pipe!

You will need two spigots altogether. You could replace the single one on the right with a twin one (see pic below), but there's not much room for the pipes and coupling the hoses.

What with needing to add a valve to the copper pipe (don't use a ghastly DIY screw on the pipe gizmo please!), and unforgiving solvent weld fittings (which are the best to use, but in my limited experience you need to be sure the whole assembly is right before you start with the adhesive!), coupled with not a lot of room to work, I'd be inclined to leave it to a plumber if you get a fair quote!

 

[gjw123]

Possibly, but can't confirm that's what your plumber was thinking. That sort of thing perhaps with the first elbow mostly in the left hand cupboard, but there's a coupling where you might want to put it, so the existing T etc will probably be scrapped and re-done to suit the offset required.

With a short piece of pipe!

You will need two spigots altogether. You could replace the single one on the right with a twin one (see pic below), but there's not much room for the pipes and coupling the hoses.

What with needing to add a valve to the copper pipe (don't use a ghastly DIY screw on the pipe gizmo please!), and unforgiving solvent weld fittings (which are the best to use, but in my limited experience you need to be sure the whole assembly is right before you start with the adhesive!), coupled with not a lot of room to work, I'd be inclined to leave it to a plumber if you get a fair quote!

View attachment 94293

Ahh yeah, fair enough - thanks for your help with this.

One thing I did wonder was around the washing machine tee valve. I'm planning on getting one, as shown in the picture.

Would this replace the valve currently on the cold water pipe (the one without the black lever), or would I need to cut the pipe and add it as an addition further up?

 

[Basher]

Ahh yeah, fair enough - thanks for your help with this.

One thing I did wonder was around the washing machine tee valve. I'm planning on getting one, as shown in the picture.

That's fine.

Would this replace the valve currently on the cold water pipe (the one without the black lever), or would I need to cut the pipe and add it as an addition further up?

The latter. The black one is presumably the hot?? And the one on the right with the slot (which seems to be about 80% closed) is the cold? I'm guessing they are to allow the taps to be serviced without having to turn the water off for the whole house.
Cut whichever is the cold feed in a place convenient for the dishwasher hose, and where it will reach!

The valve on the right looks of some age, and in my experience, when old they can leak after you operate them. Let's hope that's the hot then!
Do you know why the right valve is largely shut - is that an attempt to reduce the flow because the hot and cold pressures are different? (If so a better way is to use a pressure reducing valve)