Could attempt to build a "frame" much like a wall frame, but have the edges set higher. Then fille the frame holes, or dead space with golf balls, then place a sheet of plywood cut to fit within the frame, I included a mockup made in Paint.. Nothing special, ill see if I can upload something better, hopefully you get the idea.
The Black would represent the raised edges of the frame, (put a sheet of plywood on bottom side as well), the red would represent some 2x'4s cut to length, and maybe use 2x2 pieces as the cross bars within the frame to seperate spaces of golf balls. It'd give the same effect, and would cost about... $25 at most, maybe less i you already had some plywood to use on it.Could then try somehow attaching handrails or building handrails maybe that somehow run off the wall or some better way to fit regulations. Anyway, I made one of these myself and it works great, Ive used it in home haunts, but as I will be moving to the Commercial Haunt level for the 2013 season. If you have any questions about this just ask!
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