I need to replace my porch columns and was thinking about using steel pipe. I was thinking of using something up to 4" OD. It's a small porch with a small gabled overhang, so I only have 2 posts to replace. It's a wooden overhang and a concrete porch. Any thoughts as to the pipe's wall thickness or how to attach it to them to the porch? Pros and cons? Thanks for the help.