Expert: Bruce E. Johnson - 5/3/2011

Question
My patio is approximately 36' long with 2 end pillars and 3 interior pillars that support the roof.  I would like to remove the 3 interior pillars and replace with a composite beam to bear the load of the roof.  Do you think that would be possible?  Is it the most cost effective solution?

Answer
Hi Pam,  a 36' span is pretty long for a single span.  The biggest problem you may be facing is headroom.  A beam capable of spanning 36' will be at least 24" high so at this point I don't know what your existing head room is and if your ceiling height can handle a 24" beam running across it.  Even if you were to split the span into two 18' spans you will be looking at at least a 16" tall beam.

You didn't mention how your roof is framed.  If it is framed with say 2x8 rafters then it may be possible to install a beam at the ends of the rafters and use rafter hangers to hold them up.  This would allow your new beam to be raised the thickness of your rafters, in my example here that would be 8". This method would eliminate any overhangs or eaves you may have now but allow for a deeper beam.

I hope this information helps, please feel free to write again regarding this or other matters, sincerely, bruce e johnson..bejohnsonconsulting.com