OSB (Oriented Strand Board)
Engineered wood panel made from compressed wood strands, used for sheathing and subflooring
OSB (Oriented Strand Board)
Oriented Strand Board (OSB) has become the dominant sheathing material in modern construction, often preferred over traditional plywood due to its consistent quality and lower cost. OSB is manufactured by compressing multiple layers of wood strands with adhesive, with each layer oriented perpendicular to the next for maximum strength. This engineered process eliminates natural wood defects and provides uniform structural properties throughout the panel.
Why It Matters
OSB provides critical structural support and weather protection when properly installed. For roof decking, it creates a solid base for underlayment and shingles while resisting wind uplift. For wall sheathing, OSB braces the structure against racking and provides a nailing base for siding. Modern OSB includes tongue-and-groove edges for easier installation and enhanced performance. In San Diego's climate, choosing proper thickness and ensuring proper installation with appropriate gaps for expansion is essential.
Common Applications
- Roof decking: 7/16-inch or 1/2-inch panels over rafters or trusses
- Wall sheathing: 7/16-inch panels over wall studs for structural bracing
- Subflooring: 23/32-inch tongue-and-groove panels over floor joists
- Rim boards: Vertical orientation at floor perimeters
- Temporary construction barriers and work surfaces