Plywood versus OSB on Subfloors, Wall and Roof Sheathing

Huber offers a 50 year warranty on its improved OSB panels and Georgia-Pacific offers a lifetime warranty on its enhanced plywood. Those types of warranties suggest each company truly stands behind its product. Summarized below are the pros and cons of using plywood and OSB.

Plywood and OSB are considered in the construction industry as structural panels and building codes allow them both to be used for subfloor construction, as well as wall and roof sheathing. This said, each has their unique advantages and disadvantages. Plywood is constructed out of glued layers of wood veneers that are orthogonally stacked upon one another and are hot pressed together. This type of construction yields a strong structural panel that is resistant to contraction and expansion and is lighter than OSB, however it is susceptible to delimitation if exposed to water.

OSB, on the other hand, is constructed from short strands of wood (a few inches in length) that are crisscrossed with one another and are glued and hot pressed together, similarly to plywood.

OSB panels are heavier than plywood, however it absorbs less moisture than plywood. This said, OSB is prone to edge swelling if water comes in contact with it and takes longer to dry out than plywood. For these two reasons, I have always been leery about using oriented strand board panels, particularly on roofs and on subfloors where I knew ceramic tile flooring was going to be used for the finished floor. Roofs are prone to water damage and ceramic tile requires level and solid subfloors. If water comes in contact with the OSB during the home construction or remodel inevitably it becomes necessary to replace the bad sections and/or sand down the swelled edges. So with the improvements made in the manufacture and construction of both plywood and OSB structural panels the real deciding factors come down to mainly cost and availability.

OSB has traditionally been less expensive than plywood and thus why many large builders prefer it over plywood. This said, plywood still offers some structural benefits over OSB and thus the ultimate factor on determining the best product to use comes down to the application. In my opinion I still intend to stick to plywood on the roof and subfloor, assuming my budget allows for it. For the wall sheathing, with the right house wrap I could be convinced to switch to OSB.