The under-floor heating is in place, but the other workers are going to begin before the slab is poured: How do I protect the PEX tubing?

The ideal solution is the Optima castellated insulation system.
An arrangement of very sturdy studs (10 T/m² compressive strength) protects tubes from damage and allows them to be placed at a constant width.

Find out more about COMAP under-floor heating solutions

Find out more about COMAP Optima under-floor heating solutions with castellated insulation