You put a adhesive bituminous water-proofing membrane system on the outside of the concrete walls. You have to put something under the floor slab too, that ties-in to the wall moisture barrier and waterproof keyways at all joints. Then you have a sump pump on an automatic float switch 'in' a sump pit on a sloped slab (under the shooting deck) that pumps-out anything that enters through the shooting ports. I imagine they have a peremeter 'sock' drain at the top of the walls (at or just below roof level) that collects roof run-off dumps into the cornfield. The roof probably has a bitumin membrane and cavity drainge/protection board that dumps into the 'sock' pipe. I imagine shooting port lids would be a must to keep rain out when not in use. I also imagine something this elaborate is powered through underground EL service. Lotta money in that pit.SHANE704 wrote:how do you keep something like that from filling up with water?
Just my thinking.
