waste pipe under kitchen sink

Hi,

During the course of investigating a blocked waste pipe, I've been forced to become more familiar with the kitchen plumbing as installed by my house's previous owners.

Firstly, how much of a problem is it if the pipe after the u-bend (between the main soil pipe and the u-bend) has an upwards gradient? The current installation has a slight upwards gradient, which (not least) I think means the sink does not empty quickly.

I think it has this upwards gradient because a sink and dishwasher have been plumbed in between the u-bend and the sink. This has pushed the waste-end of the u-bend lower than originally intended. Does anyone know if there's a way of plumbing in the dishwasher and washing machine to bring the u-bend outlet higher? Can I just insert a small length of pipe to achieve this?

Finally, the pipe to the waste pipe and the u-bend have been joined particuarly badly. Basically, there is no seal/o-ring and the pipes are different diameters! I can't see how it could ever have sealed properly (to unblock the pipe, I had to unscrew it and it now no longer seals). What's the best way to join these pipes together?

Suspecting this job may have hust got larger than anticipated ....

Miles

Reply to
miles
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I think you can get adjustable traps for this sort of problem

Reply to
Stuart Noble

On 23 Nov 2006 02:09:44 -0800 someone who may be "miles" wrote this:-

Not only will it not empty quickly, but debris is likely to accumulate at the lower end, leading to a blockage. If the pipe went downhill slightly then the debris would be washed along with the water.

Take a look at the various traps with inlets for washing machines. There are some models with a minimum distance between the inlet and outlet of the trap. One of these might be enough to bring the outlet of the trap up to a suitable height and you wouldn't need to adjust anything else. These tend to be the ones with angled inlets for washing machines.

Alternatively consider replacing the trap with one without machine connections. Then either do the machine outlets properly with standpipes and a new connection to the stack, or if there is space there are running outlets that can be clamped onto a horizontal pipe.

Replace them.

Reply to
David Hansen

These days I'd say most people would use one of these:-

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plumb in a WM/sink/DW - the hoses from the WM / DW attach directly to the trap - B&Q and the likes have them

Jon

Reply to
Jonathan Pearson

Actually, that is exactly what it is all plumbed in with at the moment, but the extra length for the WM/DW fittings means the trap outlet is not high enough.

My current favoured option is to replace it with something more like

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the waste pipe at least has a downhill gradient, and find some other fitting to link in the WM/DW (for example, giving them their own traps).

Does this sound feasible?

Thanks for your help!

Miles

Reply to
none

It's almost always easier to take the whole lot out back to the pipe sticking through the wall and start again with new traps, pipes and fittings. It's not a big job or expensive.

A
Reply to
auctions

On Thu, 23 Nov 2006 15:13:33 +0000 someone who may be none wrote this:-

easily with scraps of food.

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might be small enough to get the waste pipe going in the right direction and you could connect the dishwasher to it, carefully to avoid siphonage. Then you only have to deal with the washing machine, by one of the methods already suggested.

Reply to
David Hansen

When I purchased a 'Designer Pack' for a Franke sink, cum taps, cum waste system it included a system Franke Plumbing Kit - LIRA 2.

This is really a waste management system with adaptors to the sink wastes and connectors for washing machines, dish washers etc. The 'core' of the system is a horizontal tube which acts as a manifold to which the 'sources' connect then a 'U - bend' hanging off the bottom of the manifold. A sketch is worth a thousand words -

towards the bottom of the page..

Reply to
Brian Sharrock

I agree - it's quite clear that this botch should be ripped out and started again.

There is a reason why whoever did it like this did it: the whole lot joins an iron waste pipe running inside the house which has an outlet which is too high for the current pipework.

My first impression is that to seal this outlet off, and cut a new one about a foot lower for the kitchen waste pipes to feed into is a Big Job. Am I right? Or this is fairly routine? Is it a building job or a plumbing job?

Thanks,

Miles

Reply to
Miles

What are cum taps and cum wastes ??.....

Reply to
Stuart

If you have to ask .... :)

Reply to
Brian Sharrock

On Thu, 23 Nov 2006 19:43:03 +0000 someone who may be Miles wrote this:-

The ideal solution would be to use the existing connection for the sink and make a new connection for the washing machine and dishwasher lower down. They could then have separate standpipes with a running trap between them and the stack.

Making a new 40mm connection in a cast iron stack can be done with care and patience. There are saddle adapters that will mate properly with such pipes, provided one can get all the way round them to attach the straps and screw up the fastening. Don't drop the cast iron plug down the stack, as it may stick somewhere. It helps if access to drill is reasonable.

Reply to
David Hansen

Thanks for all your help: I finally got it sorted out through a combination of replacing the old plastic pipe seals, and a very short extension that puts the outlet of the existing trap just a tiny bit higher (but enough to make a difference).

I'll leave the larger-scale changes for when it's time to redo the kitchen ...

Miles

Reply to
Miles

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