Expert: Bruce E. Johnson - 5/29/2011

Question
Hi i am in the process of opening up a wall between the kitchen space and my living room to make it a big open space. When we took down the wall we found out there are 4 1by 6's supporting the weight above. (which is our master bedroom and the roof above). The  weight above is supported by this beam and concrete walls at each end and they are 16 ' apart.  Right below the middle supporting beam is the metal supporting beam  in the basement.

My contractor is considering to replace the middle beam with the the horizontal beam which will consists of
4 1by 10's together resting on the concrete walls at both end. The concrete extends to the basement floor..   

Please advice me
Thanks
Brian

Answer
Hi Brian, I don't have enough information to really give you a good quantitative answer on your potential beam sizing.  However a rule of thumb for support beams is one inch of depth per foot of span for a 4" beam.  In other words for a 6' span you would need a 4x6, for a ten foot span you would need a 4x10 etc.  The composite beam you are describing "4 1x10's" is basically a 4x10 but I am not a big proponent of 1x material being combined for beam construction unless it is laminated and glued together properly.  Giving the 4 1x10's the same value of a 4x10 would mean that the span of the beam be ten feet.  You never mention what the actual span is.  Please feel free to write again regarding this or other matters, sincerely bruce johnson..bejohnsonconsulting.com