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TedSlick TedSlick is offline
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Join Date: Apr 2002
Location: So.Cal
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Cary, that's a great way to do it, spreading the load over rafters, if possible.

Let's see, the 4x4 becomes the beam in that case. If the ceiling joists are spaced 24 in.:

500lbs x 24 in = 12,000 in-lb
divided by 7.15 cu.in. ('S' for 4x4): 12,000/7.15 = 1,680 psi bending stress on the 4x4.

LOL...theory says a cheapo 4x4 might be in jeopardy in that case. I take it you never had a problem...so, perhaps it was a good piece of lumber. Then there's always the diff. between theory and reality
Old 01-28-2004, 12:36 PM
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