What should the new light shaft be filled with?

Hello,

my name is Horst and I am new to this forum. Thanks for letting me join!

I need your advice:

One of the light wells at the house is cracked and needs to be replaced.

In the next few days I will excavate the well with a mini excavator.

When installing the new well, I want to proceed as follows:

- approx. 10 cm layer of gravel
- coat the masonry with bitumen
- attach an insulation mat to the masonry
- install the light well
- fill all around with gravel or pebbles up to the top edge of the well

What grain size should the gravel and pebbles have?

Do the gravel and pebbles need to be compacted?

If so, with what?

Which insulation mat?

I assume that a drainage system is installed around the house. However, I am not sure.

Thanks for your input and greetings from the Westerwald

Horst