My room is 13' x 28', 'Man Cave.' I Would like to know what is best, 3/8" or 1/2", and if the second grind material is good?

Our Regrind Rolls would work perfectly as flooring in a man cave. These rubber rolls are very durable and are easy to install and clean. For this space, you can honestly go down to a 1/4", but if you were choosing between the 3/8" thickness and the 1/2", 3/8" is plenty.