On 23/07/2019 18:30, Andrew wrote:
Just core drill into the inspection chamber so that
the hole is above 'high tide mark' and seal with
silicon. Make sure you have a downfall, but not too
steep all the way.

The trap under the sink will provide the necessary
smell trap.


Sounds too easy, I was assuming there would need to be a separate gully
trap outside before the connection to the inspection chamber.

AJH