With lumber supplies high and prices falling, lumber manufacturers are looking at decreasing production. All of this will help bring lumber prices more in line with the prices of oriented strand board (OSB). Since both of these materials can be used for a wide range of construction projects, pricing is now less of a consideration. However, there are a lot of other factors that will come into play when making a choice between plywood and OSB. Let's take a look at some of these factors.
Applications
The advantage in this category goes to OSB. Why?
While both materials can be used for walls and roofs, plywood is not a viable choice for flooring unless it is for subflooring only.
The Manufacturing Process
The advantage in this category goes to OSB. Why?
The plywood manufacturing process involves the use of very thin panels of lumber called plys. The plys are pressed together and glued to create plywood. In most cases, the very top and bottom layer or two are made with a hardwood veneer while the middle panels are made from softwood. This makes the manufacturing process a little more expensive and complicated.
The OSB manufacturing process involves the use of many smaller pieces of hardwood and softwood that are mixed together into panels. The manufacturing of panels is much less complicated because the materials through the panels are uniform. This allows manufacturers to manufacture larger panels.
As a point of reference, plywood is usually manufactured in 6-foot panels while OSB panels could be are big as 12-foot panels.
Appearance
The advantage in this category goes to plywood. Why?
From an appearance perspective, plywood is a lot more attractive. It actually lends itself to being a better-finished surface because it has the ability to hold paint and stains. The ability to hold finishes comes from the fact that the top layers are made from veneer lumber that lends itself to holding finishes.
Conversely, OSB is made from a uniform process that includes softwoods that don't effectively hold finishes. That limits OSB to be more useful as a material that fits better beneath a finish material, such as siding, unless you are looking for a unique finish like the one below.
The Installation Process
The advantage in this category is neutral. Why?
Aside from being able to buy and use larger panels with the OSB option, the installation process for builders with these materials is almost the same. Both options require the builder to size the pieces, set the pieces into place against the joists, and nail or screw down the pieces securely.
The fact that OSB is a little more flexible can be both an advantage and a disadvantage. It really depends on how and where the panels are being used. The biggest advantage includes the fact OSB is easier to walk on because the top layer is not made from a hardwood veneer. The biggest disadvantages include the weight and flexibility of OSB. It's a heavier material, which makes carrying it a bit more of a challenge. The flexibility issue makes it more difficult to carry and work with when fitting pieces together.
Dealing With Moisture
The advantage in this category is neutral. Why?
This category matters a lot in regions where builders are likely to encounter a lot of rainfall during the construction process. The primary advantage for OSB is it more resistant to moisture absorption. The problem it presents is it takes the top layers longer to dry, which can result in construction delays.
Conversely, plywood absorbs more water faster, but it also dries very quickly. From a potential damage perspective, plywood is subject to more permanent damage if overexposed to water in high rainfall environments.
Durability
The advantage in this category is neutral. Why?
The water absorption problem rears its head when it comes to durability. OSB is a more durable material. However, the fact it takes longer to dry exposes the material to swelling and warping in a wet cold climate. OSB is perfectly suited in warmer environments with less rainfall, areas like the deserts of Arizona or Nevada.
Plywood may not be quite as durable, but it does have a track record. Good pieces of plywood if properly finished and maintained can last as long as 50 years. Honestly, OSB as a building material has only been available for a few years. It's impossible to predict how long the material will last into the future. With that said, OSB is quite durable if maintained and finished properly before moisture can become an issue. Longevity questions will likely be answered in about 30 more years.
Eco Friendliness
The advantage in this category goes to OSB. Why?
Since OSB is made with smaller pieces of wood, it can be created from smaller trees. Smaller trees are easier to farm specifically for the purpose of manufacturing OSB.
Plywood is made from heavier materials that have to come from larger trees. That forces manufacturers to rely more heavily on existing forests for raw materials. That doesn't sit well with environmentalists who are well aware the OSB options are available.
As a side issue, OSB does require treatment with certain chemicals (formaldehyde) that are not actually eco-friendly. Conversely, plywood lumber does not require chemical treatments.
Note: OSB is available without chemicals, but it is very difficult to find, which makes it a bit price restrictive.
The Cost
Circling back to the cost, the current building environment puts everything on a level playing field. In the future, plywood prices will likely climb, leaving OSB as the least expensive option under most circumstances.
For more information on the current market conditions of both OSB and Plywood read:
- Current State of the OSB Market in 2021
- Current Plywood Market Conditions in 2021
