Selecting the right engineered wood for a project can be a tricky and overwhelming endeavor, especially if two or more of them have similar properties. OSB and MDF are often confused, but they are different materials that have other uses. Understanding what they are made of and ensuring that you are picking the right material for your project is crucial.
OSB is considered to be stronger than MDF. OSB is suitable for structural projects and withstands water, moisture, and weather conditions better than MDF. However, MDF is more versatile and easy to work with than OSB and preferred for projects requiring a smooth finish.
A study was actually conducted and published in 1995 to test for failure of composite woods including OSB and MDF. The study found that when the materials ensured stress, the lifecycle of OSB was significantly longer than MDF. in fact, at 70% stress levels, OSB was structurally sound for over 10,000 cycles why MDF was found to fail at an average of just 405 cycles (source).
While OSB and MDF are similar engineered woods, they have significantly different characteristics. Understanding what makes them so unique is the first step to picking the best material for your project.
What Is OSB?
Firstly conceptualized in 1963, OSB or Oriented Strand Board is a type of engineered wood. It is composed of several strands of lumber, which are set perpendicularly.
The wood strips are also placed strategically in a way that supports layering. This manufacturing choice allows the wood to become incredibly strong and supports 50 layers of wood strands. It has given plywood a run for it’s money in recent years as the structural sheathing of choice (source).
The strands are layered and compressed with an adhesive, usually synthetic resin or wax. The adhesive is applied at high temperatures and high pressures, ensuring that no space is left between the strands.
The wood strands used in the production of OSB usually derive from small, quick-growing trees. Some of the wood you will find in them might come from aspen poplar and southern yellow pine. This characteristic makes this wood particularly strong and sustainable (source).
This engineered wood is strong, compact, and easy to work with, all characteristics that have made it extremely common.
What Can You Use OSB For?
Understanding the nature of your project might offer you valuable insights on what wood you need to use. However, as a reference, OSB is an ideal material when it comes down to completing larger-scale structural projects than MDF (source).
Depending on the scale of your project, you might pick one of the OSB types available today. These include:
- OSB2: Ideal for structural, non-load bearing projects or dry conditions
- OSB3: Better for load-bearing projects and in humid conditions
OSB can be used for both internal and external projects because it is weather-resistant. You might decide to use this wood for:
- Flooring
- Workshops
- Sheds
- Roof or wall sheathing
- Creative DIY projects (such as headboards, noticeboards, cabinetry, furniture, drawers, etc.)
As seen, OBS is weather-proof. However, if you need it for permanent outdoor use, you might need to consider adding an extra layer of weather protection.
Tips for Using OSB
There are several tips to keep in mind when using OSB. These can improve or decrease its strength and versatility. Here are some of the most important ones:
- Commonly, OSB panels are stronger when placed towards one direction compared to another. This characteristic emerges from the way the wood strips are placed at the core of the board.
- Ensure all edges are supported. Use studs, noggins, or joist to ensure all edges are supported. This strategy will allow you to prevent the boards from moving.
- Use the right type of nails to fix the OSB wood. Nails that are too thin will not help you to keep the wood in place. However, if the nails are too thick, they will splinter, damaging the wood.
Pros of OSB
- OSB offers you a consistent density.
- It is highly versatile.
- You can find it in most sizes, some larger than plywood.
- It is a durable and robust option.
- It is highly cost-effective.
- It is a pliable material.
Cons of OSB
- It can be challenging to paint.
- Only some types are waterproof.
- It can be heavy to lift and move.
- It can suffer from swollen edges and corners.
What Is MDF?
MDF or Medium-density fiberboard is a viable alternative to plywood. MDF is straightforward to work with and can yield optimal results. One of MDF’s most-loved characteristics is that, unlike regular wood, it does not boast knots or warping.
This characteristic translates into smooth surfaces that are not likely to crumble or splinter. MDF is easy to saw or tear with precision. Since it is not as strong as OSB, MDF is more suitable for smaller projects, such as decorative items and furniture-building.
MDF is composed of wood shavings and sawdust, which are dehydrated and then mixed with an adhesive. This adhesive comes in the form of wax or resin.
As the two parts are blended, the mix forms a panel. The panel is then pressed under high pressure and heat. Under this compression, the board will become rigid, and the external layers will start to harden.
Before entering the market, the panels are sanded and completed with a finishing, which gives them a smooth finish and allows for more precise cutting.
What Can You Use MDF For?
MDF is enormously appreciated for its high versatility and affordability. It can be extremely durable and robust, depending on the type.
You are likely to see the best results if you decide to use MDF for projects such as:
- Cabinetry
- Shelving
- Furniture
- Flooring
- Decorative projects
- Doors or door frames
Tips for Using MDF
Like in the case of OSB, MDF has unique characteristics that need to be considered when working with this material.
Here is what to keep in mind:
- Avoid using a hammer against MDF panels as these are incredibly dense. Therefore, the nails are not likely to go through it if you have not pre-drilled a whole. Use a trim nailer instead.
- Avoid putting your MDF panels in contact with water or moisture, as they are not water-resistant. When exposed to water, MDF tends to crumble.
- Opt to use a solvent-based primer before painting it. This strategy will allow you to avoid the sandpaper effect. Once the primer dries, sand it before painting it (source).
- When you are cutting MDF, ensure you are protecting your face from the sand it produced. Additionally, keep a new saw nearby as much sawing can impact the saw’s edges.
Pros of MDF
- Working with MDF is similar to working with real wood.
- MDF is more pliant than timber.
- It is more user and budget-friendly than wood for small projects.
- It is easy to paint.
- It is an affordable engineered wood.
- It is smooth and does not cause splinters if well maintained.
- It is easy to cut as it is uniform.
- It is stronger than particleboard.
Cons of MDF
- MDF can be extremely heavy because of its high density.
- It is harder but not as strong as OSB.
- It crumbles when exposed to water or moisture.
- If you are cutting several panels, you will notice the blades getting duller.
OSB vs. MDF: Which One to Pick for Your Project?
Above, we have seen all the characteristics that allow you to consciously pick the right wood for your upcoming project. However, if you still have some doubts, the video below can help you decide on the best type of engineered wood.
Alternatively, check the table below to examine all the best characteristics of OSB and MDF.
| OSB | MDF | |
| Strength | Medium strength | Medium strength |
| Water resistance | Depending on type | no |
| Ease of Working | Heavy, but easy to cut | Easy to cut |
| Sustainability | Sustainable | Less sustainable |
| Easy to paint | Yes (with primer) | Yes (with oil-based primer) |
Conclusion
OSB is an excellent material if you are looking at starting a structural project, but you are budget conscious. It is also more suitable if you are looking to find a material that withstands water, moisture, or adverse weather conditions.
Whether you are looking at creating a wall or just furniture, OSB should be the material to choose. Additionally, this is one of the most eco-friendly and recycle-engineered woods out there.
On the other hand, MDF is a highly versatile engineered wood that is extremely easy to work with.
Related Reading:
- Can OSB Be Used for Interior Walls? Here Are The Facts
- Installing Tongue And Groove Siding Over OSB
- OSB Versus Sheetrock In A Garage: Pro, Cons, And Fire Code
- Can I Use MDF As Underlayment? Critical Considerations
As a homeowner, I am constantly experimenting with making the structure of my house more energy-efficient, eliminating pests, and taking on DIY home improvement projects. Over the past two decades, my family has rehabbed houses and contracted new home builds and I’ve learned a lot along the way. I share my hard-learned lessons so that you can save time and money by not repeating my mistakes.
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