ICC - International Code Council
 
Cart                                                                   
Skip to main content
 
Home
About ICC
Codes & Standards Forum
Membership / Chapters
Codes, Standards & Guidelines
Education & Certification
Store
Education & Certification
Misc

Your ICC Account

Email:
Password:
Bookmark and Share
Green Building Certification

Codes & Standards Discussion Forum 

Welcome to the ICC Codes & Standards Discussion Forum

The Code Council has revisited how best to provide an online, professional Discussion Forum and area within the website that has a sense of community – where Members and nonmembers can provide input and exchange ideas with their peers in the industry. The new Codes & Standards Discussion Forum does just that, as it allows Registered Website Users and ICC Members to discuss the I-Codes in an online community.

Members Area Codes & Standards Discussion Forum

Note to Nonmembers: If you join the ICC you can have access to important building safety information!

Members Area Codes & Standards Discussion Forum

As an ICC Member, you have access to the Members Area of the Codes & Standards Discussion Forum. Follow the link to discuss the Membership Councils and other benefits of being an ICC Member.


6 post(s) First 1 Last
Search 
Required Sheathing Thickness
This forum is under moderation. Your reply will appear when it is approved.
Required Sheathing Thickness By  Samuel Imbriaco

Posts: 2

9/30/2011 3:30:17 AM

When replacing all old sheathing with new sheathing and the rafters spaces are 24" o.c. what whould the the thickness of the sheathing be according to the 2009 IRC?

Also, Whe doesn't the City's that are supposed to be inforcing these codes don't enforce them?

Report Abuse     

   

Required Sheathing Thickness By  Uncle Bob

Posts: 174

9/30/2011 8:06:20 AM

 Posted by Samuel Imbriaco

When replacing all old sheathing with new sheathing and the rafters spaces are 24" o.c. what whould the the thickness of the sheathing be according to the 2009 IRC?

Also, Whe doesn't the City's that are supposed to be inforcing these codes don't enforce them?

Samuel,

Welcome to the forum.

According to 2009 IRC, Table R803.1 Minimum thickness of "lumber" roof sheathing; rafter spacing 24"; would be 5/8".

and, for Wood "structural panel" sheathing (R803.2.2 Allowable spans); you would go to Table R503.2.1.1(1) to determine minimum nominal panel thickness.

Many code requirements are not inspected.  Section R109 Inspections; are generally considered "required inspections" by the Building Safety Department; and some of those are excluded by amendment or by the building official.  R109.1.5 gives the building official authority to conduct "other" inspections.  Most cite lack of inspectors and/or time restraints as reasons for not conducting some inspections.

Always contact your local Inspection department for amendments and local requirements.

Hope this helps,

Uncle Bob 

 

Retired Texas Combination Inspector. Location Oklahoma.

Report Abuse     

   Edited By Uncle Bob at 9/30/2011 8:11:58 AM.

Required Sheathing Thickness By  Mule

Posts: 22

9/30/2011 9:35:49 AM

Pay attention to what UB is saying... "lumber" which is the plank type sheathing is required to be 5/8" where "structural panel" is your OSB type of sheathing, which could be as thin as 3/8"

I've had other inspectors call me before and say "You know what I just read??? Desking on houses have to be 5/8" " I said... No! that's when lumber is used!

Ohhhhhh now I see!

 

Mule

Report Abuse     

   

Required Sheathing Thickness By  Heckle

Posts: 12

10/4/2011 9:41:20 AM

7/16 " osb or plywood is the minimum you can use without edge support. some departments do not have the man power to do roof sheathing inspection, inspectors can not see everything and assume that the builder knows enough to do some things right. The stamped span rating on the sheathing will over ride the code.

Report Abuse     

   Edited By Heckle at 10/4/2011 10:23:26 AM.

Required Sheathing Thickness By  cynthia cruz

Posts: 1

10/5/2011 10:15:06 AM

1/2"

Report Abuse     

   

Required Sheathing Thickness By  mtlogcabin

Posts: 242

10/5/2011 3:46:20 PM

Depends on the roof load see TABLE R503.2.1.1(1)

I am in a minimum 46 psf snow loads (live load) for roofs. According to the table 7/16" OSB or plywood with a 24/16 rating installed with 24" oc trusses/rafters is only good for 40 psf so 15/32" or 1/2" are the minimums in my jurisdiction.  

ICC does not stand for Intentionally Clear and Concise

Report Abuse     

   

6 post(s) First 1 Last
Standards Boost Business
2015 I-Codes