View Full Version : Strength of steel compared to lumber
EPMiller
Oct 19, 2008, 10:30 AM
I have wondered about this in the course of my work. What thickness of sheet steel would be needed to be equal in strength to a piece of dimensional lumber? Example: 2 pcs 2x6 spruce supported at the ends (5-1/2"H x 1-1/2"W actual), bolted as a sandwich on either side of what thickness sheet of steel to increase the strength equivalent to one more 2x6. Second, would that same thickness steel work with 2x8s or 2x10s to do the same job? Would it have to change thickness for different spans?
Just one of the many questions that come to mind when working on construction.
cdad
Oct 19, 2008, 11:50 AM
Here is the problem with your line of thinking as I see it. Steel is a product that has high sheer strength so in order to use it in construction it must be reinforced. To do that you end up with an I beam. That way the top and bottom plates are ridged. So sandwiching steel between 2 beams of would might add some strength it doesn't add to regidity unless in the form of an I beam. So it would be best to replace the wood with an I beam type construction when going for strength. Steel when flexed can caus heat and also melt so flat a piece of steel would be out of the question.
EPMiller
Oct 21, 2008, 06:39 PM
I am aware that usually steel beams are done in I shapes. In this case, the "sandwich" will be restrained, so that all the force would be in the vertical direction. This is just to beef up the vertical strength of a header. As to movement, wood doesn't work too well either if there is much movement.
EPM
cdad
Oct 21, 2008, 07:04 PM
This might help.
Question: Sizing Steal Beams to replace already spec'd wood (http://uclue.com/?xq=966)
Bottom of page.