What sort of tradesperson do I need for this job?

[BasinHaircut]

The pipes on the outside of my house that take the water from the sink/bath upstairs are quite long and go round the corner of the house. the sink and bath pipe go into a sort of container (I don't know the right word) from which another pipe comes out and goes down into the drain.

We have 2 issues, firstly, the water, when coming out of the pipes that go into the container give splash back onto the house. I'm assuming either the pipes are too short or the container needs a lid.

Secondly, the pipe that goes down Into the drain doesn't really go into the drain. It stops at the mouth of the drain (as does the one for the washing machine) and so when water with soap/detergent goes through it sometimes foams up and all the foam/bubbles come out of the drain. Again, I'm assuming that if the pipe was longer then the water wouldn't splash and create bubbles.

It's not really the job of a builder or a plumber is it?

Try a plumber. They teach about drainage etc on plumbing courses

I second plumber. The container is called a hopper.

Thanks both, for some reason I assumed that plumbers only did inside!

We had similar issues with pipes into a hopper, we had new pipe work, improved runs and improved connections done by our plumber to solve the problem (water now all goes down the pipes, no splashing, overflowed or foaming from the hopper)

definitely a plumber.