Kitchen Sink Drain - Again

[Joe4542]

Hi guys,
I'm in the progress of re-doing my kitchen, but will soon need to do the waste pipes and could do with some advice.
I've stuck a quick pic (its crap..I know) which will hopefully make what Im saying clearer.

I had planned on the pipes being in a sort of 'T' shape with the Sink trap (with dishwasher feeding onto one of the Spigot pipes) on the right side of the 'T', the Washing machine using a standpipe arrangement being on the 'Upright' part of the 'T', and the left part of the 'T' goes through the wall out to a hopper on a drainpipe (we're in first floor flat).
Still with me???
I was going to ask what sort of 'fall' I should have on the pipes, the Sink branch being appx 80-90cm long to the t-piece, and the Wash machine branch being appx 50cm long. But then I realised that the sink trap would be about 60cm from floor level, but washing machine trap - due to standpipe arrangement would be much lower...
Would it still be poss to join the two branches at a t-piece and run one waste through the wall - even though the sink branch would have something like a 30deg fall on it, to the t-piece?? Or am I likely to have to drill two separte exits for the Sink + washing machine drains??
Obviously I'd prefer not to have to do the latter cos
1) It'll take ages to drill two holes with the core drill
2) I think it looks ugly when there are pipes coming out of the wall outside...

Any help greatly accepted, O wise ones


Sorry for posting again!

 

[Bahco]

You can share the wastes but do try not to have them draining at the same time if possible.

1 inch fall per metre will do you fine.

Check that your drains are combined as you are supposed to keep grey water separate if they are not.

Can't be bothered to read any more of your post sorry.

 

[Joe4542]

Ok Thanks for replying Bahco,

I did wonder if the post was too long, and so did TRY to keep it brief

1" per metre was something around where I was normally thinking, but then theres the problem of the height difference between the two runs, and so a steep drop on the Sink branch...

Whilst I'd aim to keep the top of the standpipe above the sink waste (to presumably reduce the chance of water coming out of the washing machine standpipe, would I be likely to have any other problems due to the steep pipe drop

TA

 

[Bahco]

Would I be likely to have any other problems due to the steep pipe drop

Can't see why as there are no solids likely to block up the pipe.

 

[Joe4542]

Ok, thats what I was thinking too, but I remember reading somewhere that steep pipe runs can cause syphonage and suck the water out of the trap, or at least maKe it ...
GURGLE GURGLE GURGLE

(good sound effects eh?)

Joe

 

[Bahco]

Fit an anti vac waste then to make sure.