built up wood beam suppor

huangyhg

built up wood beam support
i have a situation where a group of 4 2x4's were used to create a wooden beam.  the current situation is that the beam is supported at the ends with a steel steel pipe column supporting the beam at about a quarter of the distance from one of the ends.  the new situation will be to install 2 new pipe columns at about the third points.  the pipe columns have a steel plate welded to them at the top.  does this plate need to span all of the beam's 2x4's?  if so, can a 2x4 be used as a seat to support the 2x4's in the beam?
thanks.
four 2x4 is not much of a beam!
if the bending, shear, compressive stress and deflection are within acceptable limits an additional bottom plate is not needed.  
preferably, the column cap plate should be as wide as the beam (6").  i'm not saying a flatwise 2x4 will not work as a cap plate, but the steel cap plate is better.
daveatkins
depending on the span, load and species of wood used, you should check if there is sufficient contact area between the column plate and the remaining wood to keep  fc|| from being exceeded