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6x6 lumber post max load

  1. May 28, 2010 #1
    This should be a pretty simple but I am having trouble finding the right information.

    For a 6x6 wooden post for now well say 12' above the footing I need to determine the max load vertical load it can take before it fails. I live in Canada so was looking around Canadian lumber standards and stuff like that for span and load charts but cant seem to find them. I'm hoping an engineer cant link me to something.

    I have a Canadian handbook of steel construction which provides everything fro steel so I need something like that but I don't wanna go out and buy another 150 dollar textbook.

    And no its not for school or work related its a personal project I am going to be doing on property my mother owns.
  2. jcsd
  3. May 28, 2010 #2
    These people are on your doorstep.
    All civil engineers should know of COFI


    I have some american standards tables, but properties vary widely depending upon the grade and type of timber:

    Southern cypress, douglas fir,eastern hemlock,southern pine,redwood,eastern spruce.

    American dressed lumber actual size is 5.5 x5.5 section properties available, max tensile stress, max horiz shear, max compressive stress, youngs modulus - if we can narrow the timber choice down a bit, or send me a PM with an email address so I can scan the table to it.
  4. May 28, 2010 #3
    The compressive strength of (wet to dry)
    Douglas Fir is 1300 - 1700 psi
    Hemlock, Western is 1300 - 1650 psi
    Pine, Eastern white is 960 - 1200 psi

    note: if the 6x6 is more than 20 feet stabilizing becomes necessary to avoid bending moments.
  5. May 28, 2010 #4
    Are you planning to apply your own safety factor or are you really looking for the maximum allowable load capacity? The capacity of a 12' tall 6x6 post varies greatly as described above. For maximum design load you should be safe using 400 psi, that's about 12,000 lbs. But you need to add up the loads based on values that go with your allowable stress. S
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