[mouse]

Make a mat out of Auto carpeting (boot liner) to fit under the whole kit. The stuff is synthetic and does'nt mould. You should not have your kit in a mouldy atmosphere anyway.

I suggest if you want a temporary or permanent solution for your practice area is to dynabolt into the concrete a piece of angle iron or bent alloy or such as a stop to keep the pedal from moving forward.
If you drill the hole deep enough, when you decide you don't need a bolt through the floor, you can then tap it into the ground.