the fact that it is unheated contributes to why it still is working.A very interesting link! Thanks!
In 1978, I built an attached garage on a concrete slab! At the time it seemed to me, to be a good idea to lay down 6 mil plastic sheeting, immediately under the slab and I have been well pleased with its performance!
The floor has been perfectly dry and has never cracked, even though the garage is unheated and has experienced temperatures ranging from 0F to 90F.