Kitchen island waste

youngrob · Jun 29, 2019

Hi,
Im in the process of extending my home and I'm considering installing a Kitchen Island with sink and I'm concerned about waste. My extension foundation block are in and built up to current floor level - I've yet to put in the hardcore/insulation and concrete slab. My island will be 2.5m from outside wall of the new extension, where a Back inlet gully will sit and flow into the existing 100mm soil - vented stack. Would it be normal practise to leave a channel in the proposed concrete slab and simply run the sink waste through this and into the back of the new gully? I'll be using Hep20 pipe in pipe for hot and cold supply. Any advice would be grateful.

Thanks

JCplumb · Jun 29, 2019

2.5m run will be OK in 40mm but I'd advise 50mm to reduce the risk of blockages especially if it will be difficult to access after installation. It can't go uphill at any point

oz-plumber · Jun 29, 2019

Old school mentality:

Run 110mm on grade and reduce the vertical to 50mm to pick up the sink.
I would never run 40mm or 50mm on grade through a slab under any circumstances, more so on a kitchen sink

Ben-gee · Jun 29, 2019

Just put the sink against the outside wall.

Islands with sinks are so passé darling.

youngrob · Jun 29, 2019

Thanks to you both for the advice. So if I run 100mm through does that get incased in the concrete slab (of which is 150) or does it run through the hardcore do u know -sorry more of a builder question I guess. I would then have to do a direct connection to the existing near by underground 100mm pipe and omit the BIG. I picked up the attached photo from polypipe website and that's where I thought the 50mm pipe would have been an option.

OffshoreGas · Jun 29, 2019

oz-plumber said:
Old school mentality:

Run 110mm on grade and reduce the vertical to 50mm to pick up the sink.
I would never run 40mm or 50mm on grade through a slab under any circumstances, more so on a kitchen sink

Totally agree, the extra £20 in materials is nothing compared to having to dig up your floor because you scrimped the first time.

youngrob · Jun 29, 2019

Yep I agree. But i dont know where the 110mm pip should sit in the floor. I dont want to put my concrete in now until I know where it should sit. The building regs doc seems unclear.

OffshoreGas · Jun 29, 2019

youngrob said:
Yep I agree. But i dont know where the 110mm pip should sit in the floor. I dont want to put my concrete in now until I know where it should sit. The building regs doc seems unclear.

Best thing you can do is speak with BCO, they are generally keen to help you get it right and happy to help.

youngrob · Jun 29, 2019

Yes that's a good shout. Thank you.

Aire · Jun 29, 2019

If you've got the depth then fit the 110mm into the hard-core, cover in pea gravel then concrete over.

Kitchen island waste

youngrob

JCplumb

oz-plumber

Ben-gee

youngrob

OffshoreGas

youngrob

OffshoreGas

youngrob

Aire

Similar plumbing topics

Newest Plumbing Threads