Im building a couple 4x8 tables on casters that will have a 4x8 flood table on top of frame. So my question is would you put plywood over this frame? I will have 8 7gallon smart pots in each table. This will not be a table i fill with water just something to protect floor and so run off drains to waste. I dont think i need to put plywood on since 2x4's are 16 inch centers and a flood table will be on top. Am i good to go like this or am i setting my self up for problems not buying plywood?