solid post or multiple studs

huangyhg

solid post or multiple studs?
i have a client who is insisting that using multiple studs in a framed wall (residential construction) is the same as using a solid wood post that equates to the same dimensional lumber. for example, he insists that (2)2x4 spf#2 studs nailed together will support the same vertical or lateral loads of a 4x4 post.
how do i convince him that he is wrong?
thanks..
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wager him $1000.
are you sure he is wrong?  if so, show him your calculations and your sources for your calculations.
compare with fabricated steel beams. i would have thought that it depends on the amount of nailing to take the horizontal shear for lateral loads and whether the nails can work loose. otherwise it should be the same for the same grade of wood.
(2)2x4 does not have the same dimensions as a 4x4.  there's a start.
however, if you run the numbers, you may can get adequate strength from the doubled/tripled studs, and not need the 4x4s.  that may be the point your client is making.
check the sub-heading built-up columns with mechanical fastenings pdf page 5 of 47
question: while 2-2x4s do not have the same axial load carrying capacity as 1-4x4 post, for conventional wall construction do bldg depts sometimes accept 2-2x4s as an option where 1-4x4 is required?
the allowable stresses for sawn lumber are dependent on the sizes of the lumber for one.  as others stated above, the cross-sectional area of built-up columns is not equal to that of a sawn lumber column, for another. the strength of the built-up column for axial or lateral loads is also dependent on the connection of the individual studs to each other.  
article of shear wall end post testing
i have never worried about the nailing together of the built up members.  there is a nailing schedule in the building code that covers built up   
henri2
nice link to a popular question. i usually let it go if the the double 2 x studs are blocked at mid-height for the entire wall.