Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Continuous Beams in Residential Construction

[Subject Prev][Subject Next][Thread Prev][Thread Next]
How about cutting the top of the beam vertically at least half of the beam depth, over the center support, in effect creating two simply supported spans?  I often specify this when dealing with residential beams, especially if it is not visible.  If they are visible, specify two separate beams. The splice will be less noticible.
Pat Clark
----- Original Message -----
Sent: Monday, November 25, 2002 8:30 AM
Subject: Re: Continuous Beams in Residential Construction

I don't think my original message was sent.  Sorry if this is a re-post...
A span up to 50% shorter than the longest span should not present problems with uplift for uniform loading.  I have not been able to find a specific document that addresses this.  However, most engineered wood manufacturers publish literature on their products and allow differences of 50% or more; I'd be glad to point you to a few eng. wood sites for some confirmation of the 50%.  Alternatively, ASD (and others) publish equations for non-uniform span lengths and can be calculated by hand.  I don't believe there is a specific number that can be used, but from my experience 50% has been safe.
Tim Allison

>>> ghodgson(--nospam--at) 11/25/02 09:54AM >>>
I have run into situations, particularly in house construction, where continuous beams of unequal length have been
used.  Where there is a long span and a short span, you usually get a kick-up (uplift) at the end of the short
span.  Unless you can hold the beam end down, you get a bump in the floor.  Consequently, I try to avoid these
particular continuous beams.

I read somewhere once, that to help avoid this situation, the continuous beam spans should not vary by more than
15%.  I would like to find that piece of literature again.  Can anybody help me with this?  Unfortunately, I don't
remember if it was Canadian or American.

Gary Hodgson, P.Eng.
Niagara Falls, ON

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at:
*   This email was sent to you via Structural Engineers
*   Association of Southern California (SEAOSC) server. To
*   subscribe (no fee) or UnSubscribe, please go to:
*   Questions to seaint-ad(--nospam--at) Remember, any email you
*   send to the list is public domain and may be re-posted
*   without your permission. Make sure you visit our web
*   site at:
******* ****** ****** ****** ******* ****** ****** ********