What Is OSB?
The acronym OSB stands for oriented strand board. It was invented in the 1970s when people began expanding on what was then called waferboard. Unlike other scrap boards like chipboard or cork, OSB is made strategically.
The pieces are placed just a certain way to create a strong new, yet waste-free, board. It also uses wood from hardwood trees that grow quickly and are plentiful. The logs are cut into strands that are fit together with wax.
What Is Plywood?
Although OSB is more popular than plywood, plywood is still a more common term, often being used in place of OSB. Plywood is made differently than OSB. Plywood is made with plies of wood that are piled on top of each other.
This wood is a wood veneer and it is glued to the other pieces with formaldehyde. The layers are piled on in a cross-graining pattern so that the wood won’t split. The better the plywood, the more angles used.
What Is The Difference Between OSB And Plywood?
OSB has only just recently overtaken plywood on the sheathing market. Before a few years ago, plywood was much more popular. Now, OSB has over 70% of the market shares, which is more than twenty percent of what it was twenty years ago.
But does that mean it’s better in every way or should always be the number one choice? Of course not! Or else plywood would be extinct. The only way to compare OSB and plywood is to look at the pros and cons of each.
Pros And Cons Of OSB
Pros
· Fireproofing Option – one of the greatest benefits of OSB is that there is an option to have it fireproofed. Manufacturers can apply a fireproof seal to the wood to make it fire-resistant which isn’t something done with plywood.
· Cheaper – no matter how you look at it, a sheet of OSB is cheaper than a sheet of plywood of equal size and thickness. In some cases, OSB is half the price of plywood. But in most cases, it’s about 20-30% cheaper.
· Thicker – OSB is naturally thicker than plywood. It’s no secret that thicker sheets offer many benefits. So if you’re paying less for thicker boards, that may be enough to convince you to choose OSB alone.
· Larger Sheets – not only are OSB sheets thicker, but they come in larger sheets. You can still get them in the standard 4×8 sheets, but you can also get them as long as 24ft long. This makes large projects even easier.
· No Knots – unlike plywood, OSB doesn’t have large knots in the wood. Knots can break off and leave holes in wood and they are impossible to screw through without compromising stability. So no knot is a good thing.
· Stable – OSB is often used in place of plywood for joists along with 2x6s or 2x4s due to the extra stability of the thickness and composition strategy. Plywood isn’t recommended for adding stability to joists.
· Eco-Friendly – because OSB is made with renewable trees that grow quickly and are plentiful, it is more eco-friendly. It also can be found without formaldehyde and in chemical-free versions, if that’s a concern for you.
Cons
· Heavy – OBS is significantly heavier than plywood due to the thickness and amount of wood packed into each piece. This can become a hassle with small construction groups or when used on more fragile frames.
· Hard To Waterproof – this is by far the biggest downfall of using OSB. It is not waterproof nor permeable. In fact, the ends of OBS swell significantly, especially if cut. Plywood is much more water-resistant.
· Not Attractive – you won’t hear of people using OSB for siding or their flooring option. It simply isn’t attractive and is for sheathing alone. You will want to find something attractive to cover it with.
· Can Rot – because OSB isn’t waterproof, it can rot after a while. It will take years, but it has been known to happen. If it’s kept dry and safe, this won’t happen. But it is always a risk when using OSB.
Pros And Cons Of Plywood
Pros
· Impact-Resistant- plywood is more impact-resistant than OSB. This is why it’s often used in workshops and worktables. It won’t split or dent when under pressure like OSB can, so it’s also great for subfloors.
· Many Variants – plywood comes in many more variants than OSB. This is why it’s used in markerboards, cabinets, and even aircraft. Just hearing it can be used in aircraft makes people want to use it.
· Nearly Waterproof -plywood is quite water-resistant. It doesn’t swell much when exposed to water and is permeable, so it allows water to pass through without absorbing it. Another reason it is used in subfloors.
· Curves Well – plywood curves much better than OSB does. It is often used in curved projects like eyebrow windows. Plywood is more pliable which makes up for its thinness and gives the thickness purpose.
· Solid Wood – plywood is more attractive than OSB because it looks like solid wood. This is one of the main reasons people choose it when they do. It has the appearance of a nicer material, whether it is or not.
· Longer-Lasting – plywood seems to last longer than OSB. This is likely due to the water-resistance of it as opposed to OSB which absorbs and swells when exposed to water. However, the initial price may balance this out.
Cons
· Thinner – it’s as simple as that. Plywood is thinner than OSB. It can break easier if not handled correctly but only because it’s thinner. You can buy thicker plywood that can make up for this if you pay extra.
· More Expensive – this is the number one reason people choose OSB. It is much more expensive than OSB for large projects. For small projects, plywood is great. But if you’re investing in building materials, OSB may be a better choice.
· Knots – it may not be a dealbreaker, but the knots on plywood can be quite annoying. They can leave holes, be in the way, and force you to play which way you will lay each piece. This isn’t a problem with OSB.
