Originally Posted by deltaten
IF yer talking about the closed cell (?) thin mats generally used for exercise; I believe they *may* become soggy, or at least trap water under. ......
Closed cell material will not absorb water.. that's the "closed cell" feature - it's like a bunch of balloons bonded together, not like open cell sponge-like material.
However gluing such material down may eventually trap moisture underneath and it could be a real mess to deal with later. There is (expensive) product like treadmaster that's meant for that sort of thingn but eventually it will break down from UV and look like crap. I'd be really reluctant to do that you your nicely finished project.
Perhaps some of the drop-in interlocking rubber tile material could work.