Lets talk about my wood

In the previous posts we determined the maximum load that we can put on an 8 foot tall column made out of standard schedule 40 steel pipe.  The question now is what size pipe do we need to match the load bearing capacity of a 6″x6″ wooden column.  We care because I’m trying to replace a rotting wooden column with a column made of metal pipe.  Which brings us to point number A.  At least one of the column is rotten. Logic would dictate that a rotten column  is not of a capacity of a column that is not rotten.  Point number B is that the number of columns differs between the front porch and the back porch even though the house is fairly symmetrical.  The front porch has an extra column.  This allows the front door to be visually framed by two columns.  All that to say that the number of columns holding up the roof over the porches is fairly arbitrary and that the columns are probably not under tremendous stresses.

So, what is the allowed load on a 6×6 inch wooden column.  According to Simpson Strongtie, using best case scenario, maximum load on an 8 foot tall, 6×6 wooden post is 25,260lb.  This jives with the chart on The Engineering ToolBox.  The chart is hard to read so you know it is legit.

This is kind of shocking to me.  A 6×6 wooden post (under ideal circumstances!) can hold up 12 tons.  Way to go, Nature!  This also means that the posts on my front porch can hold up approximately 72 tons (on paper).  That’s almost 73 tons!

The conclusion is that 2.5″ NPS pipe is at least as strong as 6×6 solid wooden post.  This is great news as I bought four sticks of it a week ago.