Not directly a metalworking question but related... I am planning a shop building and thinking about the concrete floor thickness. 4" with wire mesh seems to be standard for residential garages and the like. I don't intent to have anything super heavy there. Maybe something like a bridgeport mill or similar size. Is this reasonable or should I be going a bit heavier? Vehicles are likely to be heavier than the equipment as one side will have about a 28' camp trailer or RV.