Expert: Bruce E. Johnson - 12/2/2008

Question
Hi- We have a open beam home built in '72, our house is shaped in a large L, we removed walls surrounding the kitchen and are left with two wooden supports connected to the large timber running along the ceiling, we had a structural engineer come out to ask what we needed to do to remove them and he didn't really tell us we could or could not remove and reinforce with say metal plates, the longest part of our house is like 30 feet, we know much longer open beam houses have been made, so what really are our options, inserting an I Beam under for support, keeping support beams in place, metal plates?  Is there a book we can purchase and research ourselves?

Answer
Hi Vicky, what exactly did the engineer say?  I'm a bit confused with your terminology.  When you say you have a large timber running along the ceiling are you describing a ridge beam that the rafter beams are connected to?  If so, then that beam is a structural beam meant to hold up the rafters.  By removing the posts your rafters will push out the walls as the ridge beam and roof collapses.  You might be able to keep this from happening by bolting collar ties between opposing rafters.  These will keep the rafters from pushing the walls out that they bear on.  
As far as beam sizes go, if you are going to install another beam underneath the existing one you would need like a 6x24 wood beam or an LVL beam (laminated plywood), or a steel I-beam..As far as research goes you can look up beam span tables and rafter span tables on the internet for steel and wood beam spans.  Just type "beam span tables" into your browser and see what comes up.  

Without actually being able to see your conditions it's hard for me to be any more specific.  I hope you didn't pay the engineer for his advice which was apparently lacking.  I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com