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Can OSB Be Used Outside? (All You Need to Know)

Oriented Strand Board or the OSB is an excellent substitute for waterproof and moisture-resistant wood. It has these quality features that you won’t find in any wood material or boards. Typically, the wood is processed and engineered to create a better version.

It has a natural, consistent nature to resist moisture. Decoration can be done by using the OSB panels. But can you use them outside? Let’s find that out.

Can OSB be used outside? 

OSB or Oriented Strand Board can be used outside since it can resist moisture and survive in the rainy season. You can expect to use the OSB inside and outside the house and get the best user experience. You will get the flexibility to use it for different purposes.

You cannot expect to get the 100% waterproof service since it’s a woody material. If you want to use it outside the home, you should make the surface moisture-resistant. You will only be able to do that by applying a sealer on the OSB. 

You can also paint the OSB baseboards to make them waterproof and resist moisture. 

It will also help make the surface durable and protect it from outside threats. You can do both the work by applying a paint or coating with a sealant. You will find different primers for the OSB baseboard. You should apply them first before you paint the surface. 

The OSB will cover your outside wall, rooftop, and other exposed areas from the direct sunlight. Especially if you live in a winter or summer country and want to save your home from excessive heat or cold, the OSB might be an excellent cover for your outside wall.

You can directly install the OSB sheet outside the wall and expect it to protect your drywall from damage. If you cannot rely on the OSB quality, you should paint your outside OSB walls and give them a protective layer to save the wall from rainwater and direct sunlight.

Apart from that, you can also use the OSB baseboards inside the house. You can use this woody material as a subfloor and cover your house floors. 

Can OSB be used outside if painted?

The OSB can be used outside if painted. Typically, people suggest painting the OSB to get a waterproof surface and use it for a long time. When installing the OSB outside the wall, you need to paint the OSB to get an exact color or adjust the OSB.

It will look better after painting. Besides, the painted OSB will help you directly install it on the drywall and other areas. The outside wall will look better if you install the beautifully painted OSB. Also, the paint will give your OSB an extra protective layer. 

Therefore, the paint will protect your OSB board from external damage.

You cannot install the row OSB material outside the house. Therefore, painted OSB boards will be a real blessing. You can buy the painted OSB and install them directly outside or inside the house. 

Is OSB suitable for outdoor use?

The OSB is suitable for outdoor use because of its moisture-resistant features. Typically, the OSB material can easily resist regular sunlight and other threats. But it is not 100% waterproof, and the water can destroy the material from the inside. 

Therefore, you must paint the OSB before installing it outdoors.

You can also buy the painted or sealed OSB material and install it outside the home. It will protect your OSB and give you the most extended lifetime. If you want to enjoy the OSB service, you must paint it. Only then will it be ready for outdoor use.

Will OSB hold up outside?

If it’s properly painted and sealed, OSB will hold up quite well outside. Wood strands and waterproof resigns are used to make OSB which is considered a versatile engineered wood panel. 

OSB is water-resistant to handle the slow rain, but problems arise when heavy rainfalls because it is water-resistant and not waterproof.

This can be handled by proper sealing, coating and painting. If no corners are left uncoated, the OSB will act quite as waterproof. Good quality OSB with proper coating and painting can survive for decades outside your house.

Is it OK for OSB to get rained on?

It is OK for OSB to get rained on. The OSB boards are made by engineering process with wood strands and resins that resist water. So usually, just the board itself is water-resistant; it can handle light rain and showers. 

Above that, Proper coating, painting and sealing are done over the board. 

This helps seal all corners of the board, which mainly absorbs water. The finished OSB can handle a good amount of rain and last for a very satisfying amount of time for the buyer. 

In a nutshell, you can use the OSB board outside the wall, and it will protect the wall from rainwater if you paint it using waterproof paint or sealant.

3 reasons why OSB can be used outside

You will find three reasons to use the OSB outside your home. The moisture-resistant feature and the waterproof usefulness will turn the OSB material 100% perfect for outside uses.


The durability comes first when installing the USB outside the house. It is not like wood that will damage the wall or other material once it gets the rainwater. This feature will also insist you use the OSB outside and inside the house.

You cannot use anything weak outside the house; The materials must have some quality build to ensure durability. Here, the OSB material will ensure that you can safely install it outside the home.


The OSB material will easily resist the moisture and won’t allow the snowfall and regular water to damage the OSB material. That’s the main reason why you can use the OSB material outside your home. 

Waterproof feature:

The OSB material is not 100% waterproof, but you can turn the surface into an impervious surface by painting. You can also use a sealer to waterproof the surface. You know it is crucial to use a waterproof surface outside the house.

It will help you install the OSB material outside the house and paint it to increase its durability. You will find different OSB sealers to protect the surface from the water.  

Can you treat OSB for outdoor use?

You Can treat OSB for outdoor use. Each strand of wood that makes up an OSB panel is covered in a layer of resin and wax, which seal the strands and bond them together. 

Because of the process, its moisture resistance is greatly improved, and it is also significantly stronger than other panels. 

Its moisture resistance is comparable, if not superior, to that of plywood, making it an excellent choice for use in outdoor applications. 

The surface can be milled with various profiles, such as board and batten, or it can have a rough or smooth texture. Different finishes offer protection to the wood against moisture, mold, ultraviolet light and insects.

How do you seal OSB board outside?

You can seal the OSB board outside by following some simple tips. They are:


Create a plan, and then cut the OSB into pieces you’ll be working with. Keep in mind that whenever you see a piece of OSB board, you are required to waterproof the edge(s) that you cut and the board itself to prevent any water damage.  


Sand the OSB panel to create a suitable surface for adhesion. You could use a palm sander with sandpaper with a grit of 100. The best surface effect can be achieved by finishing with 220 grit.


Use paint designed for the exterior of the space where you will be placing the board if you intend to paint it to add color or additional protection. Ensure that the paint has been allowed to dry for the amount of time specified on the paint label.


Put on some of the sealants. Protect the OSB from moisture by sealing it with a sealant designed for the OSB board outside. Coat the surfaces of the board and edges with the sealant, using a paintbrush to apply it. 

Allow the coated pieces to dry or cure for 10 to 15 hours.


After the pieces have dried, turn them over and coat the other side if it is necessary. If additional waterproofing is required, repeat the process. After following the entire process, you will successfully seal the OSB board outside.

Final Thoughts

Since OSB has some excellent features, including moisture resistance, and durability, you can use OSB outside your house. You can also turn it into a waterproof surface to protect the OSB boards from rainwater and other threats. It will surely help you to install it both inside and outside.