Are there any charts on-line to give static loads that can be placed upon dimensional lumber say 2x10 or 2x12 or multiples of such that make up a beam ? Looking to make runners for a 8' wide by 10' long wagon bed that will hold a 1100 gal poly tank filled with 11.67#/gal material. Something similar to this one below. It had a pair of single beam runners that measure 4"x10" but over time have sagged some in the middle. They are supported approx 1 foot in from each end making the span approx 8'. Just wondering how many dimensional lumber 2x10's or 2x12's would give adequate strength and resist bowing ? Always heard that multiple laminations were stronger than a single member where wood is concerned. Thought about 4 2x10's or 4 2x12's for each of the 2 runners and either lag screwed together or using long carriage bolts to secure them Probably overkill on design but I want it built heavy duty and prefer the bed be made of wood components instead of steel for corrosion reasons.
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Lumber strength
