Standpipe for dishwasher connected to same outlet as sink

[pkdays]

Hi, I'm just finishing installing a new kitchen and have put in a new sink and dishwasher which are basically next to each other.

I am wondering about the best way to connect the waste hose from the dishwasher. I personally would like best to use a standpipe as i have always found they work better than a spigot connected under the sink.

However, I live in a top floor flat and there is only one waste outlet to the outside drain and putting in another for the standpipe would be too big a job that I don't want to embark on. Therefore I would like to connect the standpipe to the same outlet that the kitchen sink waste pipe goes to using a T-piece.

The standpipe will be under the kitchen worktop and its maximum height comes up to about to 2/3rds the depth of my kitchen sink and my concern is that if somebody fills the sink the brim and then drains it, that the water will make its way up the standpipe and spill out under the worktop.

Is this a valid concern and if so what should I do about it?

 

[Madrab]

As long as your waste pipe is at least 40mm then you should have no issue with backflow up the standpipe.
Only reason you would get that is if the water couldn't evacuate quickly enough because of too small a pipe, not enough fall or if blocked.

P.S. Oh, wouldn't hurt to have a Anti Vac added to the sink waste to avoid any syphoning.

 

[pkdays]

As long as your waste pipe is at least 40mm then you should have no issue with backflow up the standpipe.
Only reason you would get that is if the water couldn't evacuate quickly enough because of too small a pipe, not enough fall or if blocked.

Yes, I'm using 40mm pipe and the sink uses that as well. Thanks very much indeed, that's very reassuring.

 

[Madrab]

P.S. Oh, wouldn't hurt to have a Anti Vac added to the sink waste to avoid any syphoning.

 

[pkdays]

P.S. Oh, wouldn't hurt to have a Anti Vac added to the sink waste to avoid any syphoning.

I presume the anti-vac is some kind of a valved vent? And I'm guessing that would be fitted after the sink's p-trap?

 

[pkdays]

P.S. Oh, wouldn't hurt to have a Anti Vac added to the sink waste to avoid any syphoning.

I presume the anti-vac is some kind of a valved vent? And I'm guessing that would be fitted after the sink's p-trap?

 

[Madrab]

One of these might do - Pop it inline on the 40mm waste

http://www.mcalpineplumbing.com/air...l-1-189-multifit-tee.html?id=1053&category=90