They look alike and are the most commonly used sheet materials in homebuilding, but OSB (Oriented Strand Board) and plywood are very different. The construction industry began using plywood first, but OSB has become a popular choice for many contractors over the years.
So what are the differences, and which would make better garage wall panels?
Read on to see a detailed description of OSB vs plywood for garage walls. First, here is a close look at each panel.
OSB Garage Walls
OSB is an engineered/manufactured wood. Although it resembles plywood, it is structurally much closer to particle board.
It’s made up of wood shavings and adhesive compressed together under heat and high pressure. This results in a rigid structure, perfect for many construction projects.
There are three types of OSB.
- Standard OSB: Standard OSB has no special features and is perfect for floors, walls, or roofs.
- Zip OSB: A waterproof panel for the outer shearing of roofs and walls.
- Subflooring OSB: A smooth and robust board, usually with tongue and groove edges for easy connection.
Many people like OSB garage walls because they don’t require large, mature trees to make them. The waste material from lumber milling or wood shavings from small trees can make the boards, so it’s more sustainable.
When to Use OSB
OSB doesn’t warp as easily as plywood and accepts nails well, especially when punching them into ceiling joists or studs. That makes it ideal for exterior walls, roof sheathing, sheds, floors, etc.
The main issue is many homeowners, myself included, see the rough texture of the surface wood flakes and perceive it as cheap and inferior.
Having a smooth surface with OSB garage walls is impossible unless you cover it with something like drywall. The texture will not go away even if you paint an OSB garage wall panel.
But if you’re not looking for silky smooth walls, or if the OSB will be hidden behind other things (such as in storage shelves), then OSB is a great choice considering its low price.
I don’t recommend OSB for small projects, however. Tough-to-cut edges make it difficult to cut clean lines and attach other pieces of OSB or wood.
What is OSB Like to Work With?
OSB has unique quirks that will affect how (and where) you use it.
Rigidity
Since it is not one continuous piece of wood, OSB garage walls aren’t as rigid as plywood and tends to flex or bounce more. Therefore, in applications like flooring, you need to use thick or high-grade sheets and ensure the joists are close to each other.
Water Resistance
Although OSB sheets resist water initially due to the adhesive, they can soak up the moisture after continued exposure. When they become saturated, OSB garage walls will swell and expand. It doesn’t typically return to the previous size when dry. Drying also takes some time.
Pros:
- Very affordable
- More sustainable than plywood
- Initially water-resistant
- Usually thicker and more durable
Cons:
- Expands when water soaks in
- Lower shear-strength
- Cheap-looking textured finish
Plywood For Garage Walls
Plywood combines multiple thin sheets of wood or veneer glued together with the grain in the adjacent layers rotated up to 90° to one another.
This rotation, called cross-graining, is crucial because it gives plywood some added benefits compared to a solid piece of wood. It improves dimensional stability, has a higher shear strength, and minimizes shrinkage and expansion. It also gives the panel sturdy edges, which helps when driving nails close to its edges.
A plywood board contains an odd number of sheets (usually between three and eleven) and is available in four grades:
- Grade A: Also known as the cabinet grade, this type has smoothly sanded faces with no voids.
- Grade B: Coming right after grade A, this one also has smooth surfaces but may have up to 1 inch of defects.
- Grade C: Refers to unsanded boards with multiple defects.
- Grade D: With significant rough surfaces, grade D plywood is ideal for subfloors and hidden areas.
Plywood is versatile and works perfectly in various woodworking and structural projects. While plywood isn’t exactly smooth, it accepts paint well, which usually hides any defects in the wood.
What is Plywood Like to Work With?
Here are some characteristics you need to be aware of when using plywood.
Exposed Edges
Since it consists of multiple layers of thin sheets, plywood edges are not as smooth as on the faces. If you want smooth finishes on all sides, you must hide it somehow.
The most common method is edge banding: a thin strip of wood packaged as a roll with heat-activated adhesive on the rear.
Alternatively, apply wood filler on the exposed sections and then sand it to a smooth finish once dry.
However, using glue and nails, the most durable option is to cut and stick a thin hardwood strip to the edge. Even though it will leave a visible seam, the finish will withstand wear and tear better.
Fragile
The thin plywood layers are fragile and can leave splinters after cutting, resulting in an unprofessional finish. Use these tips when cutting to prevent a tear-out.
- Use sharp blades with high teeth densities
- Apply a painter’s tape over the cut line
- Make sure the cutting blade always enters on the good side
- Score the cut line using a knife first
- Place foam insulation or a scrap board on the underside for support
I recommend using a track saw with a splinter guard. Alternatively, you can find someplace to cut the wood for you.
Water Resistance
Plywood is not water-resistant, but it quickly dries after absorbing moisture.
However, repeated soaking and drying can lead to delamination because the adhesive weakens as the layers expand and contract at different rates.
Using marine-grade plywood for garage walls in wet environments is better because it has waterproof glue between the layers.
Knots and Voids
Knots and voids in low-grade plywood weaken the board and can jeopardize the structural integrity of the wall or ceiling. Consider buying the high-grade type to avoid these issues.
Pros:
- Available in different grades, depending on the project’s needs
- Returns to original size after soaking
Cons:
- More expensive
- Not as sustainable (depending on the wood used)
- Panels are usually smaller
OSB vs Plywood For Garage Walls: Differences
In this section, we will compare OSB vs. plywood for garage walls in-depth to determine which is best.
Size
OSB is available in larger panel sizes because of the way it’s constructed. The smaller, mixed pieces of softwood and hardwood are usually shavings left over from other items.
Because of this, it’s easier to make longer OSB boards than to find a large piece of contiguous plywood for garage walls.
Since plywood is a combination of multiple thin sheets of wood, it’s tough to find boards longer than six feet long. However, OSB can be as long as 12 feet.
Quality
OSB and plywood are available in different qualities, usually separated into grades.
OSB has four classifications, defined by their moisture resistance and mechanical performance.
Grade 1 OSB is primarily used for miscellaneous applications on furniture and inside your home, where it won’t get damp. Grade 2 and 3 OSB are used on load-bearing applications in dry and wet areas. If you need something heavy-duty, jump up to grade 4, which is also suitable for wet conditions.
Plywood is also available in four grades (as discussed earlier), allowing you to pick the most suitable one for your project.
Appearance
OSB has a rough, textured finish, but plywood is the opposite. It can have multiple styles and appearances, all determined by the outer layers.
Top-quality plywood usually has hardwood sheets like birch, maple, or beech on the faces. It makes visible surfaces like walls, ceilings, and furniture have a premium finish.
With low-quality softwood on the outer layers, plywood may have knots, defects, and rough surfaces, so it is not ideal for exposed surfaces. It would work well when installing the boards underneath tiles or siding to hide the defects.
OSB is similar to low-quality plywood in appearance, so it is ideal for installing underneath a finish material like tiles or siding.
If you’re not planning on covering your walls, look at OSB panels in your local home improvement store to ensure you’re comfortable with how they look.
Workability
Even though both boards are easy to use, OSB has limited uses because it is ideal for constructing walls, ceilings, and floors. You can use it in other areas, but construction work is its specialty.
However, plywood is more diverse. You can use it for flooring, roofing, building walls, furniture-making, cabinetry, etc.
Durability
When considering durability, the key thing to look at is the water resistance. OSB is more water-resistant and absorbs water more slowly than plywood.
However, it dries slowly, and once soaked, it expands and cannot return to its original size.
Therefore, the board is more practical to install in areas with low dampness levels.
On the other hand, plywood is not as water-resistant as OSB but dries quicker and returns to its original shape when dry.
Aside from that, plywood is generally lighter than OSB but lacks consistency regarding thickness due to the varying number of layers. However, both have relatively the same load strength.
It is worth noting that plywood is a tried and tested product that has been around for a long time and is known to last 50+ years. OSB is relatively new, so it lacks a proven track record for durability.
Additionally, OSB can crack more quickly, especially along the edges, but plywood withstands impact better.
New OSB types show signs of being more durable, mainly due to their water resistance.
Installation/Painting Concerns
Installing OSB or plywood for walls and ceilings requires the same procedures, but flooring is different. OSB flexes more than plywood, so the joists must be closer together to prevent bending.
Once installed, you need to give the surface a proper paint job, and plywood gives a better finish due to its smooth surface.
Some people are against painting OSB and say it is impossible, but it is possible. However, the new layer will not hide the rough texture.
Eco-Friendliness
Both OSB and plywood require trees to make them. Still, OSB is more environmentally friendly because it requires smaller-diameter trees. These grow fast on farms, making the production process more sustainable.
There is also the option of using chips and sawdust (waste products from lumber milling).
However, plywood requires mature, large-diameter trees that are rotary cut to produce the thin sheets to build the board. These take more time to grow and can lead to deforestation.
Other than that, OSB still goes through production using formaldehyde adhesives, which release urea-formaldehyde into the air. A 2019 environmental law prohibited plywood production using this glue, making the process safer for the environment.
Price
Price is a vital factor to consider, and OSB has the advantage.
It costs roughly $6 for a 4 x 8 panel, while a similar-sized plywood sheet costs $10. Installation costs are the same, so there is no need to look at them.
FAQs
Now that you know all about the differences between OSB vs. plywood, here are a few frequently asked questions you might be interested in.
Is OSB better than plywood?
It depends on the application area. If it is not as damp, then OSB is better. But if the section is very moist, plywood is the ideal option.
Consider other factors, such as appearance, but water resistance (durability) is the most critical.
Is OSB more stable than plywood?
OSB and plywood have the same strength and stability if installed properly and kept dry.
What do you use OSB boards for?
The most common uses are flooring, roof decking, and wall sheathing.
What is a good substitute for OSB?
Plywood is the best alternative, but you can also consider fiberboard, fiberglass-faced gypsum panels, diagonal boards, or rigid foam.
What side of OSB goes up on a ceiling?
The stamped face should face down into the room, and the screened surface with nail guides should face up.
Should you use OSB, Plywood, or Drywall for your Garage Walls?
- OSB is cheaper, stronger, and more environmentally friendly than plywood. It also has higher shear strength, which means it can resist lateral forces better. However, OSB is heavier, less water resistant, and less attractive than plywood. It can also swell and warp if exposed to moisture. OSB may not be code-compliant for attached garages as it is not fire-resistant.
- Plywood is lighter, more water resistant, and typically looks better than OSB. It can also be painted, stained, or varnished to improve its appearance. However, plywood is more expensive, weaker, and less eco-friendly than OSB. Plywood may also not be fire-resistant enough for attached garages.
- Drywall is the most popular choice for garage walls compared to plywood and OSB. It is code-compliant, fire-resistant, pest-resistant, easy to install, and cheap. Drywall also provides a smooth and finished look for your garage. However, drywall is weaker, less water resistant, less impact resistant, and less durable than OSB or plywood. Drywall can also crack or crumble if exposed to moisture or physical damage.
