Calculating Beam Size, span and type

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  #1  
Old 12-04-11, 01:03 PM
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Calculating Beam Size, span and type

Hey Guys,

I recently started my basement reno. Demo is 50% complete, and with all the time down there, I've been thinking about how to maximive the results.

The house is ~ 20 x 30 cape. The western half of the floor joists are supported by a wood beam running down the center line of the basement. The joists overlap the beam and span about ~10 foot.
The beam is currently supported by the block foundation and 2 steel posts. I would like eliminate the middle post to open up the area and add more flexibility.

That said, can anyone with experience help me determine what type of beam would be needed such that I could eliminate the middle post?

I'm assuming, with the correct type of modern engineered wood or steel, I could support the span and ditch the post.

What measurements are needed to determine the above?

Thanks,

Bryan
 
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  #2  
Old 12-05-11, 07:40 AM
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Beams

Good luck getting somebody to answer that question. I had an issue with floor joist deflection of over 1" and recently installed an iron beam to shore them up. There are so many variables and exceptions when figuring live load. I ended up having to wing it. As it came to be, My beam never showed. I had suspended ceilling and all i could spare was 8" of steel beam and it had to span 14'. I asked my steel supplier if he felt an 8" beam would do. I found out there were at least three different rated I beams for an 8" Iron beam.

If you are faced with moving your existing jackposts, make sure you cut the floor and get a nice thick foooting poured replacing the 4" concrete floor. I was lucky because not only did the beam hide overhead behind the ceiling but I was able to hide one jackpost in the wall and build a pocket chase for the other one surounding the jack post with 2" X 4" wall extension and drywall.

Good luck with the project.

bs5
 
  #3  
Old 12-05-11, 04:14 PM
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I'm confused by what you're calling the "middle post." If you have 2 interior supports over the 30' span, are they not spaced at 10' centers, with one at each third-point?
 
  #4  
Old 12-05-11, 04:48 PM
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Hey Guys,

I just measured the distances. THe total span from back to front of house is ~22'.

The wood beam divides the span in half, supporting ~12' floor joists with ~1' overlap on the beam.

The beam is 14 foot long, supported by the cement block foundation at one end, and jack posts in the middle and at the opposite end.

The beam itself measures 5.5"x7"x14'.

I hope this makes it a bit more clear...

Thanks!

Bryan
 
  #5  
Old 12-05-11, 10:07 PM
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Sorry, still confused. You initially had a beam spanning 30', then 22' and now 14'. Not easy to help you with those variables. Maybe you should spend a few bucks and bring in a local engineer to help you determine what you need.
 
  #6  
Old 12-06-11, 03:21 AM
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Sorry for the confusion. I will draw and post a picture later today.
 
  #7  
Old 12-12-11, 04:30 PM
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I second that, BridgeMan. Your home is your single biggest investment and people are hesitant to spend a few hundred dollars to make sure it's not going suffer permanent damage. I don't understand it.
 
  #8  
Old 12-13-11, 06:41 AM
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Thanks for the opinions guys... I get it.

I am more than willing to spend a few bucks for peace of mind and investment.

Cheap insurance, as I like to call it.

That said, who is the correct person to contact to find a structural engineer? Would it be wise to start with the building inspector and ask for available services local to my town?

Thanks,

BK
 
  #9  
Old 12-13-11, 12:06 PM
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Look for Registered Professional or Structural Engineers in your phone book.
 
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