Can anyone point to a resource or have a calculation for how much bottom ballast or weighting we need to do to our 12' tall and either 8' or 12' wide walls. They are 3/4" ply under 5/8" gyp. They are stout. UNFORTUNATELY, someone told the structural engineer that it needed to hold up to 900lbs on one side of the wall. Super-crazy and will NEVER happen, but now we are stuck with having to take all these weights in and out of the walls every time we move them. BUT until I can point to something else I have to go with the prescribed weights for liability issues. HeLp!