how much weight can a 2"x4"x6' support if the 2"x4" is laying horizontally with the 2" pt. on top and bottem?

Answer 1

Well, I do know that weight is transferred less when a structure is thinner and more compact from top to bottom, AS IN--LESS PSI, or pounds per square inch will be transferred overall. When pressure or weight is applied over a wide, thin structure, the structure will give way. When the force bearing the weight is concentrated on a structure that is stout--thin and sturdy but not wide and thin--think wallboard laying flat on the ground over 2 cinder blocks--BAD!!!, it works with less chance of the structure giving way. NOW, I must get back to freeing the world of dumbasses, of whom YOU apparently are not. Thanks for coming up with a GOOD QUESTION, I hope I gave an acceptable answer. And, as for the EXACT LOAD BEARING RATING for such timber, it's usually stamped on the raw end of the piece.

Answer 2

It depends on many factors. Where will the weight be placed on the span? In the middle? At the ends? Along the whole length? Cantilevered on one end?

Different woods have different strength ratings. Some are more than others, some are less.

A standard 2"x4" only measures 1 5/8"x3 5/8", do you really want the rating for this or a real 2"x4"?

What are you looking to do exactly?

Answer 3

Maybe you should add some info to your question. Like, are you wanting to know this for construction purposes or are you just wanting to say, build a shelf in the garage. There is a mathmatical formula for figuring the tensil strength of support timbers. But there may not be a need to get into that, depends on what your intentions are. For example, If the supports on either end of the 2x4 at a 6' span are sturdy enough, I could stand on the center without a problem (150 lbs). Load disbursement will come into play in this equation too. Like I said, maybe you should add something extra so you can get a specific response to your specific question. Thanks.

Answer 4

Hardly any, unless your building a spring board. It also depends on the cross supports underneath the 2x4