Should OSB Be Painted? Here’s A Guide to Painting OSB

Image of OSB. Should OSB Be Painted?The urge to use OSB as the new residential roofing option has been a growing priority for local contractors. That’s because this panel constitutes small dimensional tolerances, ideal for roofing. Besides, it incorporates favorable mechanical properties making it a better pick for load-bearing applications in construction and furniture production. OSB is available in different versions, with the outdoor models designed with a radiant barrier laminated on one side to ease installation. OSBs might not be finished yet, but should OSB be painted?

Yes, OSB needs a coat of paint to account for its limited durability and resistance to harsh elements. Besides, painting OSB also improves its utility and visual appeal. But ensure you prime your OSB before painting because the open strands in this panel can absorb too much paint. Priming acts as the base coat to help with the adhesion between the surface and the paint finish. It is therefore important that you don’t skip priming.

In this article, I’ve discussed different aspects of OSB and why it is important that you accord this structure a layer of paint. Please keep reading this article for more insight on OSB.

How To Paint OSB

OSB is widely accepted for its high strength and affordable price in the building industry. Sometimes it’s used as a finishing material in utility areas like basements, sheds, and laundry rooms. As such, you need to paint it to improve its appearance and prevent it from destructive elements. 

However, painting OSB has a few limitations because its surface does not accept paint. Therefore, you need special preparation before starting this DIY project. That should not worry you, as I have outlined a stepwise process to paint your OSB like a pro. 

Things You Will Need

  • Putty knife (optional) 
  • Dust mask.
  • Shop vacuums.
  • Orbital sander. 
  • Paint. 
  • Primer. 
  • Polyester resin filler (optional) 
  • Paintbrush or roller. 
  • Paint tray. 
  • Sandpaper.

Once you equip yourself with the right supplies at your disposal, you can now start the task. 

Step 1

First, wear your face mask to avoid inhaling toxic fumes, attach the sandpaper to your orbital sander and start sanding the OSB surface. I recommend using a circular pattern from the top corner working downwards to achieve full coverage quickly.

Step 2

After sanding your OSB panel, you will notice lingering sanding dust. You need to clean this dust using a shop vac or a damp rag, but not too wet. Focus on the edges and corners where most dust compiles, then let the surface dry before committing to the next step. 

Step 3

After successful surface preparation, it’s now time to prime. Take your primer and pour it into a clean paint tray. Use a wooden stick to stir the oil-based primer to attain a uniform consistency, then dab your roller into the primer and start making W-shaped sweeps on the OSB panel.

Work your way down the OSB panel while applying light coats until you attain full coverage. 

Once you’re through, take a paintbrush, soak it in the primer and start coating restricted areas where the paint roller didn’t access. If necessary, add a second coat of the oil-based primer after two hours because of the porous nature of the OSB panel.

But remember to do this only if the first coat is dry to the touch. After that, pull back to examine for surface irregularities. If any, repeat priming until your OSB’s flake pattern disappears.

Step 4

After your coats of primer dry, you can now start painting over your OSB panel. As with the primer, you will need a clean paint tray to mix the paint to resume its consistency. After that, insert a paint roller into the paint, remove it and start painting over your OSB panel.

You want to paint evenly to avoid creating high and low spots. Also, avoid using thick coats, or your paint will take longer to dry. 

Next, use a synthetic brush to paint the trim and corners where the roller can’t reach. And allow the paint to dry for a few hours before adding the second coat.

What Kind Of Paint Do You Use On OSB?

The best paint to use on an OSB panel is oil-based paint. Such paints add visual appeal, withstand high impact, and increase your OSB’s water resistance. Avoid using water-based paints on OSB panels because they will peel with time, resulting in an unsightly look needing regular maintenance.

Is It Better To Spray Or Roll Paint On OSB?

When you plan to paint your OSB panel, you will have a few decisions to make, including the application method to use. Usually, painters choose brushes and rollers to get the paint job done. But these are not the only ways to paint your OSB panel. 

There are numerous paint sprayers for all skill levels. Most beginning DIYers favor paint sprayers because they can reach the narrowest crevices that a brush can not access. With that in mind, is it better to spray or roll paint on OSB? 

It’s best to roll paint on OSB than spraying because rolling paint offers consistent coverage. Another bonus of rolling paint involves less prep work, and you can pause your project to resume another day.

In contrast, spray painting OSB integrates a lot of preparation work, and you must commit until you’re done; otherwise, the paint left in the sprayer’s gun will dry with time and cause clogs.

Does OSB Need to Be Sealed?

Yes, it’s advisable to seal OSB panels to protect the integrity of their structure, especially if it’s constantly exposed to moisture. Sealing OSB panels also increase its lifespan and prevents rotting. 

Well, as much it is necessary that you seal your OSB, determining the right sealer for your OSB is very important. The type of sealer to use will be affected by location as well as the use for the structure.

How Do You Seal OSB

As stated above, sealing OSB protects it from the ravages of moisture. Therefore, knowing how to execute this task can help your OSB panels survive years of heavy use, especially if you plan to use them for exterior application. 

Below is a stepwise process providing more insight into sealing your OSB panel. Read on! 

Step 1

Every time you cut your OSB panel, the existing sealer at the edges gets compromised, creating room for moisture to penetrate. As such, you need to measure, mark then cut the pieces you will need before sealing the edges and surface of your OSB. 

Step 2 

If necessary, paint your OSB panel with exterior paint to make it more attractive and water-resistant. I recommend painting before adding the sealer to protect the topcoat from harsh demands.

Step 3

The third step involves rolling out the sealer on your OSB edges and surface. Insert the paintbrush tip in the sealer and roll out the sealer on the OSB edges and surface. Use thin coats to guarantee consistency and ensure you seal the board on both sides instead of only focusing on the areas you made cuts. 

After that, let the sealer sit for 12 to 14 hours to dry, then turn the OSB and seal the remaining surfaces. If you need more layers of protection, add more coats of sealer, and ensure each layer dries entirely before proceeding. 

Step 4

Once you’re through with protecting your OSB panel, test it to see if you applied enough sealer. All you need is to pour some water on your sealed piece and let it sit for some hours.

If the water doesn’t soak after a few hours, it means your board is well waterproofed. If not, please add more seal coats and let each coat dry before testing again.

Is It Better to Stain or Paint OSB?

Both paint and stain fulfill the same function: to offer your OSB a solid coat, preventing it from succumbing to moisture. However, both paint and stain execute this task with different levels of success and cost. 

For instance, painting an OSB panel needs fewer coats because the paint has a thick consistency. Another bonus for painting OSB is paint is available in more color choices than stain.

Meanwhile, stains are cheaper and roll out quicker than paint because you don’t need a primer. Most stains also preserve your OSB’s natural beauty exactly when eliminating the risk of chipping due to fluctuating temperatures. 

Paint and stain also contradict in appearance regarding uniformity. Paint allows your OSB panel to accept a solid canvas of color, despite the underlying wood coloration. By contrast, stain only facilitates the natural colorations to offer an aesthetic that’s not uniform overall.

Ideally, the choice of painting or staining your OSB panel is a matter of personal preference, as both can protect your OSB panel from degrading. But if you want to keep your OSB panel from disintegrating, rotting, or becoming wet, opt for paint. 

Will Painting or Staining an OSB Make It Waterproof? 

Renovating a home or other structures can prove difficult regarding weather delays. Rain can saturate and damage your building materials and further compromise construction timelines as your materials dry out. If you’re using OSB, you will ask yourself, will painting or staining OSB make it waterproof? 

Staining your OSB panel makes it water-resistant but not waterproof. So if you intend to make your OSB water-resistant enough, use waterproof paint. 

How to Stain OSB

Staining an OSB panel contributes to its aesthetic appeal. But the dilemma sets in when applying a coat of stain on your OSB panel. The task is never easy, but I hope this guide simplifies your job. 

Step 1 

Start by placing your OSB panel on a pair of sawhorses. After that, raise the working height to minimize fatigue as you sand and stain your OSB. 

Step 2

Use medium-grit sandpaper to sand down the entire OSB surface. Then take a shop vac and vacuum up all the lingering sanding dust. Repeat sanding using 150 grit sandpaper as each consecutive sanding offers a smooth surface for better stain adherence. 

Step 3

After sanding, allow the OSB panel to air dry for some minutes. Then take your stain and stir it with a wooden stick to enclose its pigments. You do this because the stain pigments sit at the bottom of the can if left idle on the shelf for a long duration. 

Step 4 

After stirring the stain to resume its default consistency, soak an all-purpose paintbrush into it, and start applying thin and even coats on your OSB panel. Confer with the application instructions to determine the dry time between coats. Then proceed with extra coats if you want your OSB darker. 

Step 5

If necessary, add a coat of polyurethane sealer on the OSB panel for maximum protection. Once the sealer dries, sand the surface lightly with medium-grit sandpaper, remove the sand dust, and add a second coat. After that, your OSB panel is ready to use.

How Long Will OSB Last Outside If Painted?

OSB is not meant to withstand elements for lengthy periods, as it might absorb moisture and degrade prematurely. But if painted, this board will tolerate the harsh elements for about 12 to 18 months of exposure. That means you will want to paint or coat your OSB panel every time it’s exposed beyond specific measures. 

What Side Of OSB Should Be Painted?

The side of the OSB board to be painted falls to personal preference. It depends on whether you prefer a rougher texture or not. But I recommend painting on the smooth side of the OSB if you’re planning to use it for interior projects. Or paint the outer part if you will use the board outdoors.

Is OSB Better than Plywood?

Both OSB and plywood are two of the most ordinary sheet materials accepted in homebuilding. However, plywood stands out due to its high strength and versatility. Further below is an overview of their differences. 

OSB is relatively cheap and good for subflooring, sheds, sheathing, and exterior walls. That’s because it doesn’t bend easily as plywood does.

It also takes regular nails well, especially when nailing into studs below the material. However, its rough-cut edges can prove challenging to attach corners for smaller applications. 

The major downside of the OSB panel is the visual appearance. Its raw nature seems unsightly, and even if you paint it, the random texture of the wood shavings will still show through under the paint layers. 

From a structural perspective, these two boards are comparable. They constitute quality woods glued together, but OSB is more forgiving to elements than plywood.

How Do You Maintain a Painted OSB Panel?

The OSB panel can degrade if exposed to elements soon after painting. As such, it’s wise to care for your OSB board surface if you need them to last a lifetime. To help you with that, I have highlighted general maintenance tips for your OSB board. Check below! 

  • Avoid moisture

Your OSB board can withstand moisture in the early periods if it is constructed well. However, your material can get damaged by excess moisture over time. If this happens, it will rot and disintegrate, making it useless. 

So to minimize the possibility of water damage, you should keep your OSB panel dry. 

  • Sand Regularly 

OSB panels are infamous for their unsightly nature. But these boards can be very functional if maintained correctly. An excellent way to keep your OSB panel from degrading is by sanding it regularly, primarily if it absorbs water.

This way, you contribute to prolonging its lifespan. If you decide to paint the surface, please ensure you apply a coat of primer. 

If you subject your OSB panel to high humidity, use an alkyd primer as the base coat. This type of primer prevents moisture flow to and from the OSB panel to establish a lasting protective barrier.

But if your OSB panels are for indoor use, choose an acrylic latex primer as the base coat. Such primers incorporate fast-drying agents so you can paint over them within an hour. Even better, they are odor-free and do not encourage indoor air pollution. 

Note: Using primer may be optional when painting other surfaces, but it’s crucial when painting on OSB panels. This base coat allows the paint to stay attached for lengthy periods. Also, using a primer helps reduce paint consumption considering the OSB’s open strands that readily consume paint. 

Will Painted OSB Last Outside? 

Yes, a painted OSB panel will survive outside elements assuming it’s kept safe and always dry. If not, your OSB panel will succumb to the harsh elements and delaminate with time.

Poorly protected OSB will start to swell, warp and start to degrade. There are several ways that you can employ to ensure they your OSB is protected from harsh elements. Painting for instance is one way that you can use to protect your OSB, painting is the easiest and less costly to apply. You only need one coat of paint to protect OSB.

Staining is another way of protecting your OSB. Unlike painting, you will require at least two coats of stain to offer the much needed protection to your OSB structure.

Benefits of OSB Panel

OSB board graces its users with numerous benefits, which I have highlighted below: 

  • Strength and Density

One of the central selling points of the OSB panel is its strength. That is why it has outweighed plywood in popularity in terms of applications like roofing and walling over the years. This panel is twice stronger than plywood, making it an ideal candidate for projects requiring great structural integrity.

  • Consistency

Another benefit of the OSB board is its consistency, courtesy of the press technology. This makes it reliable among end-users as it lacks holes and knots found in plywood. What’s more?

The unmatched consistency allows for quick installation as you won’t encounter unwanted surprises in the OSB board’s quality, size, and shape. 

  • Eco-friendly

The wood used in making OSB panels are extracted from small and fast-growing trees. This makes for a good deal of sustainability and prevents manufacturers from chopping down huge trees that have struggled to grow for years.

Despite the endless benefits of the OSB panel, it also has drawbacks. For instance, this board is pliable, making it less suitable for flooring. Even if you use it for flooring, it will flex, causing floors to produce a high-pitched sound. 

Another issue that people dislike about OSB boards is their appearance. These panels have a traditional look making it less of a priority for those who fancy beauty. Lastly, this board is made with harmful chemicals, presenting a severe health risk. So before sanding this panel, ensure you wear your face mask to avoid respiratory issues.

Why Are the Edges Of OSB Painted?

OSB edges are painted to note the thickness of each board, avoiding confusion. They are also painted to prevent water absorption because of their porous nature. That is because when they are cut during milling, the opening remain exposed and can easily absorb the moisture. Seal prevents water absorption which can results to swelling and warping damaging the structure all together.

Whenever you are working with OSB to build a sub-floor, side wall, or sub-roof ensure that you seal all the new edges you cut or create to help protect the structure from moisture.

How Do You Keep Painted OSB From Peeling?

Paint: a cheap way of transforming your OSB panel, needs a proper application to resist wear and tear. With poor prep work and application, the outcome is a flaking, peeling, and deteriorating finish. So to avoid unexpected peeling paint soon, it pays to learn why it occurs and how to fix the problem.

Here is why your painted OSB peels with time; 

  • Improper Paint Application

Peeling paint occurs if you didn’t practice enough surface preparation, making it challenging for the paint to adhere. Proper surface preparation varies based on the OSB panel condition and the existing finish. But there is a quick process: vacuum your OSB panel with a shop vac to remove dirt and dust; when dry, use medium-grit sandpaper to scuff up the surface. This gives the primer and new paint a better texture to stick to. 

  • Using Wrong Products

Using the wrong paint for your OSB can cause peeling issues soon after application. For instance, never use water-based paints on OSB panels for outdoor projects because they will peel with time. If you’re painting outdoor OSB, remember to use exterior-grade paints and primers. 

  • Poor Painting Technique

Poor painting skills result in bubbling, peeling, and premature cracking even with the best paints, primers, and preparation. So to avoid that, begin with priming your OSB surface, then once dry, sand between coats to prep the surface for paint. Avoid painting too thickly as it will take longer to dry. 

Applying the paint in a uniform pattern is wise to avoid premature peeling. 

  • External Factors

External factors are the main culprit why your painted OSB panel peels quickly. Therefore, you should keep your painted OSB from exposure to elements like moisture and high humidity for the OSB to withstand years of use. 

How to Fix a Painted OSB Panel that’s Peeling.

Now that you’re well-versed with what causes your OSB panel to peel let’s shed more light on how to fix it once it occurs. 

Things you will need

  • A putty knife.
  • Paint scraper.
  • Wire brush. 
  • Fine grit sandpaper. 
  • Paintbrush. 
  • Primer and wood filler if necessary.

Step One

First, take a paint scraper and scrape away the loose edges, then stop immediately it becomes hard to scrape off the paint. Also, be watchful not to damage the wood’s grain with the sharp ends of your scraper.

Step Two 

Next, wipe away the loose paint using a stiff wire brush working from the edges of the damaged areas. If you notice more paint peeling off, pry it again using your paint scraper. 

Step Three

Take your putty knife, load it with enough wood filler and apply it to your OSB panel. This step requires a lot of precaution to ensure the wood filler extends beyond the edge of the damaged spot. Also, remember to flex your putty knife slightly to create a flat surface. If you apply excess wood filler, no worries; take fine-grit sandpaper and scrape off any excess. 

Tip

Ensure the wood filler dries to the touch before sanding. If not, the filler will slough off. 

Step Four

After sanding the wood filler, check for smoothness. You can perform this by running a bare hand over the patched spot to test for smoothness. The repaired areas must blend in with the surrounding paint.

Step Five

If the patched area is smooth enough to your satisfaction, apply a coat oil-based primer to prepare the OSB panel for painting. Priming is necessary to prevent the damaged area from absorbing paint abnormally. 

Lastly, paint the damaged portion using oil-based paint and ensure you blend in the paint with the surrounding area. You will need two to three coats of paint to get promising results.

How Long Does It Take for a Painted OSB to Stop Offgassing?

The VOCs from a painted OSB surface dissipate with time as the toxic chemicals evaporate. However, this can take more than five years before it finishes off-gassing. You can reduce the effects of the VOCs by mounting air purifiers inside your home or sealing the OSB surface. 

Alternatively, you can prevent off-gassing by considering the following tips: 

  • Paint with zero VOC paints and primers. 
  • Use low-VOC sealers and stains. 
  • Use natural and non-toxic cleaning supplies. 
  • Ventilate your working space properly before painting. 
  • Avoid using panels containing formaldehyde and other harmful chemicals. 

Here’s How to Paint OSB Walls

Final Thoughts

Using OSB is the best approach for construction projects. It comprises high-grade materials with consistent density making it perfect for home building projects and more robust than most composite materials. These features have made it commonplace for most professionals and DIYers. But… 

Should OSB Be Painted? 

Yes, painting OSB is an excellent way of enhancing its durability and longevity. However, this DIY task is not as easy as it sounds. That means it needs thorough prep work to avoid any adherence issues. Otherwise, you might end up with unanticipated outcomes. 

After reading this guide, you should have an in-depth understanding of painting over OSB surfaces. Meanwhile, thanks for your time, and enjoy painting.