How To Seal an OSB Board: 20 Useful Tips

Do you know the 20 useful tips on how to seal an OSB board? It is not as easy as it may seem. There are many things that need to be done in order for the sealant to be applied correctly and effectively.

The fastest way to seal osb board, is by using a water-resistant coating or sealant. You can also opt for an OSB that is already treated with a water-resistant coating.

What is OSB Board?

The first thing you need to know is what an OSB board actually is. Many people are confused about this, thinking that it has something to do with the outside of a house or building. It does not. The ‘OS’ in OSB stands for Oriented Strand Board and the material was created by the Boise Cascade company.

The material is a type of engineered wood and has been used very often in flooring, wall sheathing, roof decking, and other projects where strength is needed to hold up under high loads or weight.

Why is it important to seal it?

The reason why you should consider sealing an OSB board is that the protection will help to prevent water damage and other problems. This can be very helpful in many situations, especially if your home or business has a high moisture content due to flooding or leaking pipes for example. If there are any cracks or holes on the surface of the board, the sealer will help to prevent moisture from seeping through.

What are some of the benefits?

The biggest benefit is that it makes your home or business safer by reducing the risk of having serious problems due to water damage and mold growth. By sealing an OSB board you can be assured that all surfaces have been protected against the elements.

RELATED: OSB Meaning

How To Seal an OSB Board In 20 Easy Steps

How To Seal an OSB Board

The 20 tips on how to seal an OSB Board include:

1. You need to make sure the board is clean and dry.

The first of the 20 tips on how to seal an Osb board is;  to wash and dry the board, but don’t use a power washer, because you might damage it. It is best if you can get help from professional cleaners who will be able to do this for you without hurting your board or making any marks on it. If there are already markings that cannot be wiped off, you will have to sand the board until they are removed.

2. You need to get rid of all the moisture.

If there are still some spots on your board, you can use an oil-based primer in order for it not to stick when creating a bond with the sealant; this way they will be less likely to stick together and create bubbles or other problems. If you don’t want any stains, you may even want to use an oil-based primer.

3. You need to use a sealant that is compatible with the board.

You should always do your research before applying any kind of product on an OSB board because some products don’t fit well and they may even cause damage to it instead of protecting it from moisture. The most common types used are acrylic, silicone or urethane.

4. You should never apply more than one coat.

It is best if you only do a single application because it will be easier to work with and there won’t be any problems later on, so don’t go over the board again trying to get rid of bubbles or other things that are not supposed to there. If you have already applied a single layer, but you still need to get rid of bubbles or other things that are not supposed to be there, then it is best if you apply a thin strip on top and wait for it until dry. This way the board will look even better than before.

5. You should not apply the sealant in direct sunlight.

If you cannot get this part right, then it is best if you go inside and use a fan to get rid of any moisture that may be there so the board won’t expand or contract because of heat changes. If it gets too hot outside, your board will start expanding and you will have to wait for it to cool down before applying the sealant, or you can even try and apply a layer of clear varnish first so that your board doesn’t expand too much.

This way you won’t need to do this kind of work again.

6. You should not use a roller in order to apply the sealant.

It is best if you only use a brush or paintbrush because this way you will make sure that it won’t get too thick and there won’t be any bubbles either. If your board has already been applied with varnish, then rollers are okay to use, but if not it is best to go with a brush or paintbrush.

This way you will be able to spread the product evenly on your board and there won’t be any bubbles either.

7. You should leave the board in a cool place if you want it to cure faster.

It is best if you do this for at least 24 hours, but give it longer time depending on how thick your single layer was and what type of product has been used in order to make sure there won’t be any damage done to the wood.

8. You should remove any excess sealant with a brush or rag.

You can use paint thinner in order to get rid of the rest and it will be even better if you pour some onto a cloth instead of directly on your board. This way there won’t be any risk that there might end up being too much product, which could actually create problems later on.

This way you will be able to make sure the board looks even better than before!

9. You should always use a primer before applying your sealant.

This makes sure that the board will be protected from any moisture and you won’t have to go through all this work again anytime soon, so it is best if you do this as fast as possible. If there are already some markings on the wood, then sand them off before you apply the primer, but make sure there are no stains left because these will be hard to get rid of if they stay.

This way your board will have a better-looking finish.

10. You should always test a small area before you apply the sealant.

This way you can make sure that it will actually work for your board and there won’t be any problems later on, so don’t forget to do this as soon as possible because nobody wants to go through all of these steps again. If everything goes well, then you will be able to protect your board much better than before.

This way the sealant will actually work for your board and there won’t be any problems later on. You can test a small area in order to make sure it will look good.

11. You can use a brush, paintbrush, or roller to apply the sealant.

It is best if you only use a brush or paintbrush because this way you will make sure that it won’t get too thick and there won’t be any bubbles either.

If your board has already been applied with varnish, then rollers are okay to use, but if not it is best to go with a brush or paintbrush.

This way you will be able to spread the product evenly on your board and there won’t be any bubbles either.

13. Staining on OSB boards.

If your board is made of oak, pine, or another type of wood that can be stained, then this step should be done first before applying the sealant so it will look even better. If you plan to stain the board after you have applied the finish coat, make sure there are no bubbles left because it is best if you apply the sealant first and then go over it with your stain because this way there won’t be any bubbles or other problems.

This way you will be able to make sure the board looks even better than before.

14. Papering an OSB.

If you want to cover an area with wallpaper, then make sure there are no bubbles in the sealant and that it has dried completely before putting up your paper. It’s an important tip on how to seal an Osb board.

This way there won’t be any problems later on because nobody wants a bubbling finish coat or one where the seams will come apart after just some time passes.

This way you will be able to make sure the board looks even better than before.

15. Paint over an OSB Board.

Another tip on how to seal an Osb board is to paint your entire wall with different types of paints. Then this step should actually go last because it is best if the sealant has dried completely and nothing can get in between the board and the paint.

If you already have a layer of sealant, then make sure to sand it before you go ahead and apply your new coat.

This way there won’t be any problems later on because nobody wants a bubbling finish coat or one where the seams will come apart after just some time passes.

16. Oiling and Waxing of the OSB Board.

This step is actually more for your own convenience because it can make the board feel a lot smoother and look even better! If you do this, then there won’t be any problems later on. This will also help protect the board from moisture if that is what you are going to use it for.

17. Acclimatization of the OSB Board.

If you want to use your board as a floor or something elsewhere it will be in contact with moisture, then make sure you acclimatize it because this way there won’t be any problems later on! This is actually really easy and all you have to do is leave the board outside for 48 hours before you use it.

This way there won’t be any problems later on because nobody wants a board that will warp after just some time passes.

18. Proper Handling of the OSB Board.

Make sure you always handle your board with care and never let it fall or drop things on top of it so this way nothing can happen to it. This is actually really important and if you handle it with care then the board will last a lot longer than before.

This way there won’t be any problems later on because nobody wants a board that will warp after just some time passes.

19. Bending of an OSB Board.

If your wood floor has gotten warped for some reason, then make sure you use a piece of plywood on it and bend the OSB back into place. If this is not done properly your board might break so make sure to handle it with care.

This way there won’t be any problems later on because nobody wants a board that will warp after just some time passes.

20. Storing of the OSB Board.

The last tip on how to seal an Osb board involves storing your board for later use, then make sure it is protected from moisture and that there are no bubbles in the sealant because this way nothing will happen. This can be done by just putting some paper on top of it or even plastic so there won’t be any problems later on.

This way there won’t be any problems later on because nobody wants a bubbling finish coat or one where the seams will come apart after just some time passes.

Making OSB Airtight

You can make OSB airtight by using a variety of different methods. You can use caulk, putty, or spray foam to seal the gaps and cracks. You can also use weatherstripping around the edges of the panels.

How to Seal OSB for Exterior Use

When you intend to use it for an exterior application, you may need to use a water-resistant coating or sealant. You can also use OSB that is already treated with a water-resistant coating.

Tools You’ll need:

  • Caulk
  • Putty
  • Spray foam
  • Weatherstripping
  • Tape measure
  • Scissors
  • Utility knife

Materials You’ll need:

  • OSB board
  • Water-resistant coating or sealant (optional)
  • Caulking gun (optional)
  • Foam brush (optional)

Step 1: Measure the gaps and cracks that you need to seal.

Step 2: Cut the caulk, putty, or weatherstripping to size.

Step 3: Apply the caulk, putty, or weatherstripping to the gaps and cracks.

Step 4: Use a foam brush to apply a water-resistant coating or sealant (optional).

Step 5: Allow the caulk, putty, or weatherstripping to dry completely.

Frequently Asked Questions

How to seal osb plywood?

To seal osb plywood, you’ll need to use a water-resistant coating or sealant. You can also use OSB that is already treated with a water-resistant coating.

Can I use caulk to seal OSB?

Yes, you can use caulk to seal gaps and cracks in OSB.

Can you seal osb board?

Yes, you can seal osb board with a water-resistant coating or sealant.

Do I need to seal osb before painting?

No, you don’t need to seal osb before painting. In some cases though, it may be necessary to use a primer before painting.

Do I need to waterproof OSB?

No, you don’t need to waterproof OSB. However, if you’re using OSB for an exterior application, you may want to use a water-resistant coating or sealant.

To Sum It All Up…

In order to make sure your board looks even better than before, you should follow these simple tips how to seal an OSB board.

Reference: swiss krono