The final, optional step when laying artificial grass on any soil type is to add a bit of sand on top. This will help cool the surface in hot weather and can reduce "turf burn" if someone falls.

One of these had a layer of special open-backed 50-mm artificial turf on top, followed by a 30-mm layer of sand, a 20-mm layer of porous shock-absorbing foam, and an 85-mm-tall rainwater reservoir.

Well, they focus on the infill, not the turf. While they ban crumb rubber infill, they use alternative infills such as coconut fiber and sand instead of crumb rubber.