Expert: Bruce E. Johnson - 12/2/2009

Question
Hey Bruce, I am in the planning stage of a raise floor for an addition. Wondering why from what I have read that, when calc. beam size for a 16 x24 floor it calls for (2) 2x12s. Span on beam will (3) 8ft sections to make the 24ft. Joist will total 16ft,(2) 8ft sections( 2x8s).I will be using joist hangers for the connection to beam.They say I cannot put hangers opposite of each other on beam, is this correct? and if so can I add a third 2X12 two correct this problem.Want use hangers so beam does not too close to ground.

Answer
Hi Paul, you didn't say in your letter who says you can't put joist hangers opposite of each other.  But did they say you can't put hangers on the opposite side of the beam in an offset pattern?  Maybe it is the amount of nailing needed in the hangers when they are directly opposite of each other it destroys or weakens the wood.  Say you are using a 16" joist layout, why not offset your joists so that on one side of the beam they fall in between the joists on the other side.  You can start your plywood in the middle of the beam and lay it each direction so that you aren't trying to fight the offset throughout the floor sheathing operation.  I hope this information helps, please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com