Drainage media is made up of small, lightweight aggregate that serves as a drainage layer below the soil. In this case, it's being blown to the roof with a blower truck, but you can also lift giant sacks by crane.
Once the drainage media is in place, it is leveled to 1" - 2" depths.
Great view from the OSU Annual Trials.
Stone craned to the roof in super sacks.
Immediately after the new waterproofing membrane was installed, Chadwick ran an electronic leak detection test to ensure everything was ready to go...