Moving kitchen sink and drainage

btcp

Alderbank said:

Is your kitchen floor a suspended timber floor or a solid floor?

Which ever it is, from your description I think you are going to need a grey water pump such as  Saniflow Sanivite. This costs about £500 plus installation.
Because of the popularity of island units quite a few models of grey water pumps are now available from different manufacturers. Hopefully people who have fitted these will give feedback about their experiences and recommendations.

My floor is tiled. It’s a Victorian house, I don’t think there is anything under the floor, just levelled with the ground. 

I will research about the pump, thank you. 

plumb1_2

Grundfos are better pump units

Alderbank

If the floor is original Victorian it will indeed be just earth with a soft lime screed and the tiles laid over that. Concrete started to appear later, from about 1900.

Are you hoping to restore the original floor after installing plumbing for the island?

btcp

Is this pump basically resolving an issue with not enough fall for drainage?

btcp

Alderbank said:

If the floor is original Victorian it will indeed be just earth with a soft lime screed and the tiles laid over that. Concrete started to appear later, from about 1900.

Are you hoping to restore the original floor after installing plumbing for the island?

Yes it was built in 1860 so makes perfect sense. I will te-tile. Current tile is not original so we were thinking of using Victorian style to give it a classic look. 

plumb1_2

As it’s island the floor will be coming up, due to watere/electrical services.
get the builder to dig a trench for 2,3 or 4” drain

markin

If the manhole is 18 cm then it sound like it will work then.

It probably has to be a 4"