How to finish plumbing pipes to outside

Hi,
I have not poured the screed on my new build yet. I am about to put down floor insulation. My plumber has drilled holes at floor level for external/internal pipes (waster water & mains/boiler). There are small gaps around these pipe holes when I look at them from inside.
Question: Should I fill these holes before putting down insulation ? Should I push some concrete in there or does it matter ?

Hi, get yourself a can of spay foam from any providers, it fills gaps, insulates, and ensures flexibility around the service pipes

johnjoda said:

Hi, get yourself a can of spay foam from any providers, it fills gaps, insulates, and ensures flexibility around the service pipes

Click to expand...

Expandable foam ? Good idea.