How to Build a Box Gutter

What's the best way to build a box gutter. Here is a detail from one of my projects and I explain how it was detailed.

[@1PricelessShot]

Thats some next level Pro well done boys

[@garethwatson3051]

Nice explanation Luke!

[@lukedaviesbuild]

Thanks Gareth

[@user-bi5kh9lx6t]

Hi, would you be able to explain the purpose of the corrugated sheet metal under the Steel gutter?

[@lukedaviesbuild]

Hi Dana, it gives the box gutter some airflow under the stainless steel and also is a back up to catch any leaks or condensation from the main gutter.