Hello ! I am concerened about the plumbing in my on grade slab. Does it have to go underneath the slab 1st ,and then build your slab forms with infloor heating and pour over top . Or ! Can you put them both in the same slab? Thank you

I am concerened about the plumbing in my on grade slab. Does it have to go underneath the slab 1st ,and then build your slab forms with infloor heating and a trench and be covered by dirt, then plastic sheeting, wire mesh amd then the heating coils.our over top
Yep! That's how it's done. (see image).
All our buildings are built on slabs in my area. The plumbing will first go into a trench and be covered by dirt, then plastic sheeting, wire mesh amd then the heating coils. The pipes that do raise through the slab are insulated wiith Armoflex, (see image) Rest easy, your concerns have no basis in fact. Good luck, Tom