Archive for June, 2011

OSB (Oriented Strand Board) 2010 California Residential Code

June 1, 2011

Most builders in Oakland, CA and probably in the United States are using OSB, or Oriented Strand Board for shear wall structural panels. There was some question with the new 2010 California Residential Code as to whether this is allowed. “Table R602.10.2 -Intermittent bracing methods” describes different types of panels that are used for shear walls.

The 2nd to last definition at the end of chapter 2 of the new 2010 code defines wood structural panels. “A panel manufactured from veneers… Examples of wood structural panels are plywood, OSB or composite panels”. The definition of for “wood structural panel” includes OSB. Per table 602.10.2 that “wood structural panels” are required for shear walls in wood framed construction.

Sec. R604. requires that wood structural panels shall conform to DOC PS 1 or 2. All panels shall be identified by a grade mark or a certificate of inspection issued by an approved agency. I checked the specifications for OSB with the American Plywood association.
It appears that OSB meets the requirements of R604.

I called Economy Lumber in Oakland and spoke with Jim Dougherty who confirmed that their 1/2″ (nominal) OSB has a PS2 stamp as below.

Consequently, it appears to me as though OSB is allowed for shear wall bracing.

Please let me know if you have other information that challenges this assumption.

Rob Kelly
(510) 836-0719
fax 893-3093 cel 316-9421


Cities and Counties that I work in:

Bay Area, San Francisco Bay Area, Northern California, Piedmont, Orinda, Lafayette, Walnut Creek, Oakland, Berkeley, North Berkeley, Alameda, San Francisco, Sugar Bowl, Norden, Lake Tahoe, Inverness, Monterey, Palo Alto, Mountain View, Woodside, Alameda County, Contra Costa County, Plumas County

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Shingle style, shingle, first bay traditional, craftsman, craftsmen, bungalow, industrial, English, tudor, English tudor, cottage, farm, barn, Spanish, ski cabin, cabin, modern living

Types of Projects that I work on

Residential, residential remodel, ski house, ski cabin, ski, vacation home, vacation, homes, residences, traditional homes, traditional residences, vernacular, vernacular homes, kitchens, bathrooms, remodels, tear down, renovation, restoration