How can I Remove a Volume from inside another volume?

[ME_Mark]

Creating a hollow 'solid'

Hi all, I am trying to create a hollow pyramid with approximately inch thick surfaces. My approach was to create a pyramid and subtract a smaller pyramid using ‘boolean split/difference’. This doesn’t work since the surfaces do not intersect. Is there a better approach? If not, what am I doing wrong? Thanks you very much for your help! Best regards, Edwin

Is this what you try to realise?