Plumbing sink waste

18 Jun 2013
Reaction score
United Kingdom
I think this should be a very simple question, I'm surprised I've found it complicated so far!

So I'm plumbing in a new 1.5 bowl kitchen sink into an existing waste pipe which is 40mm and runs out through the house wall horizontally.

I've bought a McApline 40mm P trap to connect to this old pipe, and I was then going to join the two bowls of the sink together and run a single 40mm pipe down to the trap. Should be simple enough, I've seen plenty like it before

I've come across the problem that the inlet of the trap is not suitable for 40mm pipe, only the threaded connector of the sink's drain. Equally the sinks drain threaded connector is not compatible with 40mm fittings.

So really what i'm looking for is an adapter to go under each sink which converts the threaded connector to a 40mm compression connector, and the opposite to go on the inlet of the trap.

Is this a normal component, and if not what am I doing wrong?

Sponsored Links
Thanks for the reply, yeah that's a option. I really wanted to be able to tailor the pipe work a bit to the space it's fitting in, using one of those kits plus the pipework from trap to existing waste pipe would take up a lot of space in the cupboard below the sink.

No adapter type things that you know of?

Sponsored Links

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local