Mueller metal buildings
Having had a lot of concrete poured on the farm over the years I would recommend---
5 1/2 sack mix, have a fair amount of larger aggregate added( this helps spread any load pressure), 6 inch thick with at least a 12" deep footer around the edge, if using fiber mesh also use at least a reasonable amount of rebar ( I wish I had on some projects, but concrete guys talked me out of it). I know to some ,my suggestions are overkill but I want to KNOW that it will be good. JMHO
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