I have seen a lot of posts about how to plumb in both a dishwasher and a washing machine, before and after the sink trap.

What is stopping me installing the following:

1. a simple shallow bottle trap underneath the sink to make use of the cupboard space http://tinyurl.com/jubtf

2. the 2 appliance waste pipe connect after the trap using http://tinyurl.com/jn25n

3. a running trap is then installed down the run, to potentially stop drain smells coming out of the appliances http://tinyurl.com/geiz

Would you actually need the trap below the sink if I have a running trap further down the run?

Cordless Crazy wrote:
I have seen a lot of posts about how to plumb in both a dishwasher
and a washing machine, before and after the sink trap.

What is stopping me installing the following:

1. a simple shallow bottle trap underneath the sink to make use of
the cupboard space http://tinyurl.com/jubtf

2. the 2 appliance waste pipe connect after the trap using
http://tinyurl.com/jn25n

3. a running trap is then installed down the run, to potentially stop
drain smells coming out of the appliances http://tinyurl.com/geiz

Would you actually need the trap below the sink if I have a running
trap further down the run?

All you need is one of these http://www.plumbworld.co.uk/430-465 to replace
your old trap - wickes (or is it B&Q WH) sell them - you connect the WM to
one and the Dishwasher to the other (using hose clips) - to stop smells /
one draining into the other - you make sure that the WM / Dishwasher tubes
are looped over a high point (above the level of the plug hole) - there
should be a diagram on the packet of what to do

Jon

Cheers Jon.

Did not know they made these. Shame sodding Screwfix or BES (the two websites I checked and expected to have) do not sell them!

Solves the problem easily.

1. a simple shallow bottle trap underneath the sink to make use of the
cupboard space http://tinyurl.com/jubtf

Building regulations require for a kitchen sink a minimum diameter of 40mm
and a seal depth of 75mm. This trap has the diameter, but only 38mm seal.
However, you could argue that your downstream trap meets your requirements,
provided it has a 75mm seal.

http://www.screwfix.com/app/sfd/cat/...08026&id=48341

Has a 76mm seal and would meet building regs even without a downstream trap.

Would you actually need the trap below the sink if I have a running
trap further down the run?

Technically not, but it would stop dishwasher/washing machine smells coming
out of the sink.

Personally, I don't bother with all that. Washing machine/dishwasher get
their own traps with standpipes. Sink gets its own trap. Wastes are T'ed
together after the traps with no shared traps until you get underground.

http://www.screwfix.com/app/sfd/cat/...08026&id=18640

With this method you don't get one appliance's smells coming out of the
other.

Christian.