Do I need to vent kitchen sink waste?

[a1topdog]

I need to run approx 4m straight length of 40mm kitchen waste. This will be connected to the kitchen sink and a dishwasher. I will put rodding points at either end of the 4m pipe.

Do I also need to vent the pipe? I thought I read that if the pipe was over 3m a vent is needed, but I can't find that reference now.

 

[denso13]

I'd go with 50mm pipe for that length and it shouldn't need vented. You can reduce it to 40mm at the sink.

 

[a1topdog]

Thanks, that sounds ideal. You you get a 50mm to 40mm tee connector? I've had a look and can't find one.

 

[denso13]

You could fit a 50mm tee with reducers as required

https://www.toolstation.com/solvent-weld-tee/p58851

https://www.toolstation.com/solvent-weld-reducer/p27594

 

[Madrab]

You need to watch the ABS from Toolstation. I've tried the Aqualflow pipe recently, the pipe is much heavier than other ABS pipe (OSMA/Floplast) and is around a mill larger, so if it's not their pipe with their fittings then make sure you use plenty of glue.

 

[a1topdog]

Thanks for the advice all.