I think you would just be building an attic for there heat to rise into, it would make the cluster cooler. The popular option of this is a material above them to absorb moisture but not there heat, burlap bags, wood chips, wool, towels.
I used wood shavings last year with some dry sugar below, worked good, I checked the shavings once a month and only 1 started getting to wet and had to be changed, works great to wick away moisture. Keep creating , have fun.