OSB vs. Plywood: Which Subfloor & Sheathing Wins on Cost, Strength & Moisture
OSB (Oriented Strand Board) is a mat of compressed wood strands glued in cross-oriented layers. Plywood is thin wood veneers bonded with alternating grain directions for strength.
Builders call both “the subfloor,” but they behave differently under a spilled bucket or a tight budget. Homeowners see flat panels and assume they’re interchangeable, yet the wrong pick can swell, squeak, or bust the budget.
Key Differences
OSB costs 15–30 % less, has consistent strength, but swells at the edges when soaked. Plywood handles moisture better and feels stiffer underfoot but carries a higher price and occasional voids.
Which One Should You Choose?
Pick OSB for dry, budget-driven builds. Choose plywood for bathrooms, kitchens, or coastal zones where moisture is constant. Hybrid jobs—OSB subfloor plus plywood under tile—balance cost and resilience.
Can OSB be used in bathrooms?
Yes, if edges are sealed and topped with tile backer board; otherwise prolonged moisture can cause swelling.
Is plywood always stronger?
Not necessarily; 23/32″ OSB matches 3/4″ plywood in stiffness, but plywood recovers better after wetting.
Does either option affect resale value?
Rarely; inspectors look for squeaks and bounce, not the panel name, so proper installation matters more.