Post and beam addition

Voting section related to Minnesota building codes.

Is there a code section concerned with the lateral resistance of the supporting posts below?

Poll ended at Fri Oct 31, 2008 8:46 am

Yes
12
86%
No
2
14%
 
Total votes : 14

Post and beam addition

Postby forumadmin » Tue Sep 30, 2008 10:44 am

A post and beam addition on a house is eight feet above grade and has area below that is open on three sides. The structure above meets the requirements of R602.10.1 Braced Wall Lines.

Is there a code section concerned with the lateral resistance of the supporting posts below?
User avatar
forumadmin
Site Admin
 
Posts: 244
Joined: Mon Feb 27, 2006 9:02 am

Re: Post and beam addition

Postby Bob Rood » Wed Oct 01, 2008 8:25 am

The code section cited applies to the post framing as well.
Bob Rood
 
Posts: 25
Joined: Fri May 25, 2007 12:50 pm

Re: Post and beam addition

Postby Ernie » Wed Oct 01, 2008 10:25 am

Sectioon 602.10.10 could be used for the posts below the porch or addition. Post bases and caps are designed by Simpson and others with load limits including fastener requirements. This hardware is designed in accordance with accepted engineering practice.
Ernie
Ernie
 
Posts: 18
Joined: Tue Apr 25, 2006 1:31 pm

Re: Post and beam addition

Postby RDavidson » Thu Oct 02, 2008 6:24 pm

I don't have access to a code book here in Maine but doesn't the IRC require that any construction not meeting the prescriptive requirements of the IRC be designed in accordance with good engineering practice? Chapter 3
RDavidson
 
Posts: 317
Joined: Thu Feb 01, 2007 2:36 pm

Re: Post and beam addition

Postby Bob Rood » Fri Oct 03, 2008 9:32 am

Yes, Sec. R301.1.3. This requirement applies to complete structural systems, not just manufactured components.
We require that post and beam type structures be laterally supported per R602.10.6.2 (portal framing) or be designed by a licensed engineer. To my knowledge these lateral bracing requirements have been code since the adoption of the 1994 UBC. From what I have seen, there seems to be little interest in enforcement.
Bob Rood
 
Posts: 25
Joined: Fri May 25, 2007 12:50 pm

Re: Post and beam addition

Postby Paul Schoenecker » Tue Oct 14, 2008 11:06 am

Well, you guys are all wrong. Before you snap at that statement consider this for a moment. We accept the general practice of building simple decks on posts and provide for lateral stability either with bracing diagonally in a horizontal plane to the house or diagonally from the beam to the posts. Nobody would suggest we support the deck laterally with bracing in a vertical plane back to the house. This is accepted because we know that the house structure, walkout wall bracing attached to the floor diaphram, main floor wall bracing attached to the second floor diaphram and so on, effectively braces the deck. The only difference in this case is that we added three walls, braced, and a roof diaphram. Many times we, as a group, have required bracing where bracing is not required. This is one example. Another good example of this would be a tuck under garage where the ceiling of the garage is a floor diaphram attached to the house wall bracing, and so on. For some reason we regulate the length of the wall sections on either side of the door where we could actually use a post. And yes, I have seen the engineering to support my opinions. Consider this before you change what we have accepted for years as good construction practices.
Paul Schoenecker
 
Posts: 3
Joined: Wed Mar 07, 2007 2:52 pm
Location: Woodbury

Re: Post and beam addition

Postby Joe Ehrlich » Thu Oct 23, 2008 8:40 am

You have verified that the structure satisfies the "Braced Wall Line" requirements. Another structural concern would be the slenderness ratio of each support post. If the width to length ratio of the post is inadequate, the ratio could be improved by bracing the post. In this case, we are not bracing the entire structure, just the individual member. The applicable code provision is MSRC Sec.R301.1.3, which requires that structural elements not addressed in the code "shall be designed in accordance with accepted engineering practice." Sec.R602.10.10 basically says the same thing. So, take your pick. It looks like the answer to your question is "yes" there is a code section that addresses the lateral bracing of the support posts.
Joe Ehrlich
Sr. Bldg. Insp.
City of St. Paul
Joe Ehrlich
 
Posts: 18
Joined: Tue Mar 13, 2007 11:05 am
Location: City of St. Paul


Return to October 2008 Questions

Who is online

Users browsing this forum: No registered users and 1 guest

cron