Expert: Bruce E. Johnson - 4/2/2009

Question
I have 2 rooms separated by an 2x4 wall 8' long I would like to open up. One side has a 15' high vaulted ceiling. On the other side, is a 7' wide room with a standard ceiling, also supported by the wall.  

While the span of the ceiling being supported by the wall is 8', the closest heavy load-bearing support is a span of 17' from one end of the ceiling to the other.

Basically, I need to support 8' of a vaulted & standard flat ceiling across a 17' span. I was hoping to use multiple 2x10s or 2x12s. Any advice would be greatly appreciated.

vaulted ceiling   
----------------           x
x              x           x nearest support
xexisting wall x           x         
x              x           x

<  -  8'   -   ><  - 9' -  >

Answer
Hi aleybourne, 17 feet is a big span for 2x12's doubled up.  Your best bet might be to use a double LVL beam of 14-16".  LVLs are laminated wood beams and because of their makeup they remain straight and true over longer spans.  They are usually 1 3/4" thick so two of them together would be 3 1/2" wide.  I have to advise anyone tearing out bearing walls and altering existing structures to seek local counsel from an engineer.  You might contact a local truss manufacturing plant if there is one and talk to them about LVLs and maybe get some information regarding spans and sizes.  Most truss manufacturers have engineers on staff who can answer questions also. I hope this information helps, feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com