Had a sample in the post today of a 20mm one from one company and the material is so light, are they robust enough for hooves and general tramping about in a stable?! Good grip and not slippy?
I've had EVA mats down in both stables for over a year and they've been great, one stable has the old horse in it and he's very happy to lie on it whereas he's previously stopped lying down on his straw bed with no mats, four shetlands use the other stable as a field shelter and mats have stood up to their constant coming and goings. None of mine are shod so don't know what impact shoes would have.
I replaced my old heavy mats with 24mm EVA ones this year and so far I am very impressed. My mare is shod and has 2 road nails all round, they are not showing any wear at all yet.
I bought 34mm EVA mats a couple of months ago. My horse has road nails and he paws the ground at feed times - the mats seem to be standing up to this just fine! Hopefully, they'll stay that way!