aluminum extrusion to replace 4x4 post

[MOOSE123]

Does anyone know how to check the load capacity of a 3" x 3" x0.125" square hollow aluminum extrusion? It would be roughly 8' or 9' long. I have found that it has the following properties:
Ix = 1.524
Iy = 1.525
Sx = 1.015
Sy = 1.017
Alloy = 6063
Temper = T-5
Area (in^2) = 1.081
Wt./Ft. (lbs) = 1.297

I'm converting my screen porch to an glass sunroom. The contractor wants to replace several 4x4 posts with these aluminum posts.

 

[jjl317]

In the US, aluminum design typically addressed by the Aluminum Design Manual (ADM) from the Aluminum Association. Newer versions have been migrating a format similar to the AISC steel design guidelines.

Example 12 of the 2010 version is compression on a square tube

Hope this helps

 

[driftLimiter]

as jjl317 said, The examples in Part VIII of ADM10 is the best place to learn how to use the aluminum code. Your lucky that your shape is a square tube, that code is a total pain for beam design, especially of nonsymmetric sections.