How strong is 2x4?
In this regard, how much weight can a 2x4 hold?
Assuming that the load is square and there is no wind, the average 8 feet 2x4 could handle around 1,000 pounds vertically. Of course, it's wise not to push the material up to its limit, use brace and alike to secure the 2x4s whenever it's needed.
Subsequently, question is, how much force does it take to break a 2x4? It would probably take over a thousand pounds to break a 2x4 in half on its short length.
Beside this, are 2 2x4 as strong as a 4x4?
Granted 4x4s when used vertically are still rather strong for most applications, but should never be used horizontally for something structural. Also remember and remind yourself (repeatedly, if need be ) that two 2x4 is NOT dimensionally the same as a 4x4. In this case, two 2x does NOT equal a 4x.
How far can you span a 2x4 ceiling joist?
The ceiling joists are 2X4s on 16 inch centers that span the 10 plus feet.