Tim Hopcraft from Logic Australia Pty Ltd dropped off some samples of interlocking flooring to try out for flexible learning centre. He provided LokMat "Hard Dry (no Holes) and medium with holes.
The "hard" and "medium" refer to the stiffness of the plastic they are made from. Softer material is used for comfort where people have to stand for long periods. "Dry" refers to the material not having holes for drainage. For a classroom, hard and dry would be needed.
The material is available with different non-slip patterned on the surface. Tim mentioned a new finish with a random stippled pattern would be ready shortly, which should be good for a classroom. This should also be suitable for covering with carpet tiles if necessary (the non slip surface of other patterns would show through carpet). The stock color for the tiles is black (from recycled plastic) but other colors are available on order.
There is about 5mm clearance under the middle of the tiles and about 5mm at the edges. It is not clear if an electrical cable could be safely passed under the edges without damage. I have asked Tim if the design can be changed to provide more clearance.