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 12-04-2012, 05:44 PM   #1
Newbie
 
Matthewandbrand's Avatar
 
Join Date: Nov 2012
Posts: 7
Share |
Default

Max spans of lumber


Ones anyone know of a location online I could find the Max span for different lumber... Ie.. 2x6 2x8... 2x10.. 2x12x
And for beams as well.. 4x10... 4x12 6x10 6x12..


And also , wen I get into the larger dementions is it better to go with a solid beam, build them out of 2 bys , or go with an lvl (to which I have no idea what it is, just read the name somewhere)

Sent from my iPhone using DIY Forum

Matthewandbrand is offline   Reply With Quote
Old 12-04-2012, 05:58 PM   #2
Member
 
Join Date: Nov 2011
Location: Hartfield VA
Posts: 25,541
Default

Max spans of lumber


What are you trying to build?
Just judging by your questions you may be better off having this designed for you then you can build it.

joecaption is offline   Reply With Quote
Old 12-04-2012, 06:09 PM   #3
Civil Engineer
 
Join Date: Mar 2009
Location: Boston
Posts: 4,116
Default

Max spans of lumber


Maximum allowable span is controlled by the species and grade of lumber (this determines its maximum allowable bending stress), the span of the element, the dimensions of the element, and the load. There are tables in most code books for common types of elements, for example joists, rafters, and sometimes beams. Allowable span is a function of the specific code enforced in your jurisdiction, so a good place to start would be by having a conversation with your local code enforcement official.
Daniel Holzman is offline   Reply With Quote
Old 12-04-2012, 07:16 PM   #4
Member
 
concretemasonry's Avatar
 
Join Date: Oct 2006
Location: Minneapolis/St. Paul, Minnesota - Latitude 45.057 Longitude -93.074
Posts: 3,694
Default

Max spans of lumber


Beyond the simplistic structural tables(psi of stress), deflection or bounce can be a more critical item if you intend to live with what you build. Very often a member meeting the structural requirements will not be adequate from a real functional aspect.

Dick
concretemasonry is offline   Reply With Quote
Old 12-04-2012, 07:59 PM   #5
Newbie
 
Matthewandbrand's Avatar
 
Join Date: Nov 2012
Posts: 7
Default

Max spans of lumber


There is no code where I am building. It is going to be far off in the country and on my own land. It will be a small 2 story apartment and I AM doing everything myself. Thank you for all of te information. I found a couple tables online that are species specific and I think I have found the correct one. I do have some pictures up of the flooring system I have started on my other thread. Please feel free to have a look anytime as I will be updating pictures to my profile as it comes together

Sent from my iPhone using DIY Forum
Matthewandbrand is offline   Reply With Quote
Old 12-04-2012, 08:09 PM   #6
Civil Engineer
 
Join Date: Mar 2009
Location: Boston
Posts: 4,116
Default

Max spans of lumber


Since you have no code to follow, you have a lot more flexibility than most people have, who are required to follow code. In your case, you may be able to save costs by designing each major framing element based on principles of mechanics rather than code books, which sometimes require overdesign of the structure.

Generally speaking, long horizontal members such as beams, joists and rafters are designed based on bending strength. Bending is typically controlled by uniform loading on the member (pounds per square foot is typically what is listed in the code book). You size the member based on bending strength, and allowable deflection. Code usually specifies minimum loading for a floor, for example 30 psf for a kitchen, 40 psf for a living room are common loads. You may want to design for lower loads, if you are confident you know what is going in a specific room. Code typically also specifies a minimum stiffness (deflection divided by length), which may also not be applicable to your situation.

The same applies to beams. Stud walls are pretty typically designed 16 inches on center, not because of strength, but generally because of considerations about installation of sheet rock or plywood. In your case, you may want to vary from standard dimensions.

What I am suggesting is that since you are not code driven, you may want to consider working with an architect or a designer, who may be able to save you some money on framing, foundation, and interior fit out, based on actual principles of engineering and intelligent design practices, rather than following a code book for your project.
Daniel Holzman is offline   Reply With Quote
Old 12-04-2012, 08:11 PM   #7
Member
 
Join Date: Dec 2011
Location: zentral Iowa
Posts: 1,129
Default

Max spans of lumber


Spacing is usually 16" on center. For douglas fir, the allowable span for FLOORS used to be 12' for 2x8's and 16' for 2x10's. I think you can only get 18' out of a 2x12.

I've heard the allowable spans have changed because the lumber is not as good as it used to be.

Yeah, let us know what it is specifically that you wish to do.
cleveman is offline   Reply With Quote
Old 12-04-2012, 10:33 PM   #8
Member
 
Join Date: Dec 2008
Location: Fairbanks, AK
Posts: 1,844
Default

Max spans of lumber


To answer one question, LVL's of the same size will carry a whale of a lot more load and are stiffer than dimensional lumber (from what I have garnered via tables and others). As well as load and stiffness needs, as mentioned above, pay attention to how much bearing there is on the ends (and/or middles) of whatever you load up. Generally, you'll need double trimmers (often need nearly, or a tad over, 2").

jklingel 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
Doug fir vs pressure treated or redwood for a painted fence? Bigb142 Painting 6 04-26-2012 09:43 PM
Milled lumber suitable for home construction? AlexHouse Building & Construction 25 02-29-2012 12:37 AM
Lumber Liquidators Bud Cline Flooring 11 10-28-2011 02:00 PM
Lumber Quality Giles General DIY Discussions 1 01-15-2011 04:10 PM
Cheapest place to buy lumber - home improvement store or lumber supplier? J S Machine General DIY Discussions 23 01-13-2011 05:17 PM




Top of Page | View New Posts

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