Durability: While durable, OSB may not be as resistant to impact as plywood, and heavy loads can cause indentation or damage. Wide Availability: OSB is readily available in various sizes and thicknesses, making it easy to find for construction projects.
OSB is commonly used for subfloors due to its lower cost, strength, and ease of use in large panels. While plywood offers superior moisture resistance, OSB provides a similar level of performance for subflooring at a more affordable price. For more, check out my Quora Profile.
“The major disadvantage of OSB is that if it gets exposed to significant amounts of water or moisture, the edges expand by up to 15% ... especially if they are cut edges. This swell will then telegraph onto the shingles or some flooring," according to PATH.
Strength. OSB and plywood are very similar in terms of strength, but plywood is stiffer than OSB by a factor of approximately 10%.
Plywood is the most common subfloor and is a popular choice because of its strength, durability,and ease of installation. Plywood subfloors are made of layers of wood veneer that are then glued together. Plywood can be used with a variety of flooring materials.
Plywood is considered the most popular material used for subflooring, it has been used since the 1950s and remains one of the top choices for contractors. Standard plywood works perfectly fine as a subflooring material, but the best option is ¾” tongue-and-groove plywood subflooring.
Both OSB and plywood are great materials for a subfloor, but in our books, there's one winner. Plywood is simply a much better product from different perspectives, from water-resistance to durability.
OSB can be manufactured into panels that are larger than plywood. OSB is more uniform, so there are fewer soft spots, such as those that can occur in plywood. OSB is less expensive than plywood. To build a typical 2,400-square foot home, OSB may cost $700 less than plywood.
For decades, 23/32″-thick OSB has been the most commonly used thickness of OSB subflooring. But a simple switch to 7/8″ panels offers several advantages for accommodating a home's energy efficiency and for ensuring the performance of finish materials and the overall feel of the floor.
Disadvantages of OSB
Not moisture proof - OSB should be kept dry and does not perform well with prolonged wetting. It can swell, warp and lose strength if left unprotected. Weaker across the width - OSB has less stiffness across the panel compared to plywood. Additional bracing may be needed for some applications.
When installing tongue and groove OSB sub-flooring panels, it is essential that you space them correctly. Sub-flooring panels will expand and contract with changes in ambient moisture.
Mold and Rot Resistance
Plywood absorbs water faster than OSB but it dries faster compared to OSB. This could be a major issue, especially when used as material for new roof installations. OSB tends to puff up like a sponge when wet, especially around the edges. This happens because of the way it's made.
Strong Lifespan: The lifespans of engineered woods can often be a key drawback, but OSB panels boast a longer lifespan, offering 30 to 60 years of dependable performance. This further makes them a cost-effective choice, as they will not need to be replaced as often.
Screws, if driven properly, prevent creaking floors. A screw firmly holds the subfloor in place, which ensures a squeak-less floor for years to come.
OSB has excellent moisture tolerance and is much less susceptible to the stress related problems of plywood, such as warping and ply separation. OSB is generally more square and has smaller dimensional tolerances. There are no soft spots such as those that can occur in plywood.
Plywood is the most popular material used for subflooring because it's strong and stiff. It comes in different thicknesses, with the thicker options being the best choice for a subfloor. The tongue-and-groove plywood is the best option because it has interlocking edges that help prevent movement.
Generally speaking, OSB absorbs moisture slower but plywood dries faster. When plywood gets wet, it typically swells consistently across the sheet and then shrinks back to its normal dimension as it dries out. OSB tends to swell along the edges and will retain a portion of that misshapen edge after it dries out.
Improper Spacing Between Panels
Like any wood product, OSB will expand and contract after installation; without a small gap between panel ends, the expansion could cause buckling. Most manufacturers recommend 1/8 inch at panel ends and edges.
For traditional plywood flooring installations, where the plywood is directly attached to the subfloor, the recommended plywood flooring thickness typically ranges from 5/8-inch (15mm) to 3/4-inch (19mm). While 3/4-inch plywood is standard for most residential subfloors, certain conditions may require thicker plywood.
There are no advantages. OSB is highly susceptible to water damage, is not as strong, is heavier, and more slippery than plywood. It is almost the same cost per sheet as the equivalent strength plywood. Plywood, per thickness, is stronger, water resistant, and lighter than OSB.
Plywood weighs less than OSB. Nails, screws, and fasteners are more likely to remain more firmly in place with plywood than OSB. Plywood panels swell less than OSB when they come in contact with moisture. Swollen plywood will also usually return to its nominal thickness when it dries out.
Plywood is better in most cases unless the panels are exposed to water or moisture in which case plywood is BARELY any better. In applications where the panel is not ever exposed to water or moisture, OSB is nearly as good.
Plywood: Renowned for its strength and durability, plywood is one of the best subfloor materials for residential projects where moisture is not a major concern. It's ideal under hardwood, laminate, and carpet.
For these types of flooring, a minimum subfloor thickness of 3/4-inch is crucial, whether you choose plywood or Oriented Strand Board (OSB). This thickness is necessary to provide a sturdy and stable base that can support the nails or glue used to secure the flooring materials.
The code requires 1 1/4" floor thickness (overall) unless it is tongue and groove plywood in which case 3/4" is adequate. Will 1/4” plywood over 1x10 plank subfloor be thick enough t ...