Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 07-05-2011, 09:55 PM   #1
Newbie
 
Join Date: Jul 2011
Posts: 1
Share |
Default

Beam support


Can I support a beam made of 3-2X12X13's on one end with a bracket made of 3-2X6's which are lag bolted into an existing 4X4 (old true dimensions-this is a very old house)? I would like to make the beam appear to be a solid old beam by clading in cypress but the beam would be made of Southern pine. I would like the beam to be resting on the bracket which would also be clad. How big would the bracket need to be if it is supporting a second floor and attic and what size lag bolts should I use and how many. I'd like to make the bracket no more than three feet long and be no more than 3 2X6 boards thick. Thank you

BobT is offline   Reply With Quote
Old 07-06-2011, 10:40 AM   #2
Member
 
Join Date: Sep 2009
Posts: 152
Default

Beam support


There are a couple issues here that need to be addressed.

1. I believe that you are overspanning your beam. Based on the 2006 IBC, a triple 2X12 beam can only span 7'2" if the beam supports two stories and the room is 20' in width (measured perpendicular from the beam). And it is possible that your room is even wider than 20'. Here is the table:



2. The table also says that you will need a minimum of two jack studs on each end of the beam. However, this assumes that you will have a continuous load path all the way to the foundation and ground. It sounds like you want to build a 'bracket" though. Does this mean that the load from the beam will pass to the bracket, from the bracket through the lag bolts, and then from the lag bolts to the existing 4x4? I would advice against this because it will induce a moment (rotational forces) in the 4x4. And it is very likely that the 4x4 was only intended to resist axial (straight up and down) forces.

3. If you still decide to go with your design method, have you considered the possibility of bolt bearing failure? In basic terms, this occurs when one side of the bolt hole (the holes in the wood) deforms due to the forces from the bolt.

If I were doing this project, I would figure out a way to shorten the beam span or invest in an engineered beam. I would also avoid the bracket support method and ensure a continuous and simple load path to the foundation.

loftezy is offline   Reply With Quote
Old 07-06-2011, 12:15 PM   #3
Mod
 
kwikfishron's Avatar
 
Join Date: Mar 2010
Location: Kansas (NCK)
Posts: 7,211
Default

Beam support


Quote:
Originally Posted by BobT View Post
I would like to make the beam appear to be a solid old beam by clading in cypress
Well thatís reassuring.
__________________
A Picture Is Worth A Thousand Words
Especially In The DIY Chatroom
kwikfishron is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Main structural support beam HELP!!! Daniel048225 Building & Construction 34 02-16-2011 11:35 PM
Alterative ways to support main beam frizbplaya Building & Construction 8 01-28-2011 11:10 PM
How to repair main support beam Jerry48ece Building & Construction 0 01-08-2011 08:38 PM
Crawl Space Beam and Joist Support Questions Fire4Effect Building & Construction 5 06-28-2009 01:07 PM
Q:Temp support to replace beam and posts on deck dougq Building & Construction 10 09-02-2008 04:24 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.