How to Paint Oriented Strand Board

OSB, or oriented strand board, is an engineered wood product often used as sheathing in walls, floors, and roofs. It is cheaper than plywood and, with no internal gaps, more rigid. Manufacturers of OSB often cover it with a water-resistant film and add borate compounds to the wood, making it toxic to insects like termites and wood-boring beetles.

Many people prefer OSB to plywood or other alternatives as it is easy to remove and screw into, as well as more environment-friendly. It’s formed by layering strands of wood, which forms a variegated surface making it hard and frustrating to paint properly. Although difficult compared to painting plywood, it is not impossible, and many DIY fans have found different ways of performing the task.

Step 1 – Choose the Best Primer

Prolonged moisture exposure to OSB can cause the wood fibers to lift and separate, destroying your paint job. Primer is essential to eliminating that potential problem for a much more professional look. Acrylic latex stain-blocking primer will hide any stains on the OSB. This also seals the paint and prevents any bleed-through. Use a block-filler primer to fill in the gaps between strands of wood, thereby giving it a smoother look. Apply two coats of primer and allow it to dry completely before painting.

Step 2 – Pick the Right Paint

Using oil-based paint is essential. Just painting the OSB like you would paint plywood will leave the OSB rougher and the paint will bleed through regular primer, while using water-based paint causes the OSB to peel over time, making it look unattractive and requiring regular maintenance.

Step 3 – Apply the Top Coat

Apply a top coat of oil-based paint in the color of your choice and allow it to dry. Repeat the process. In the end, you will have a beautifully painted OSB wall, roof, or floor that should last a long time.

Since the 1990s, oriented strand board has proven to be an economical and competitive structural panel, its production far exceeding that of plywood. Pound for pound, it is stronger than steel and concrete, and unlike those, it is made from a completely renewable resource. Due to its low impact on the environment, high availability, and low cost, it is a great alternative to plywood.

Paint Oriented Strand Board FAQ

What kind of paint do you use on OSB?

Oil-based and latex-based paints are most commonly used on OSB. These paints adhere well to OSB and help to provide moisture resistance to make the board more durable.

Can you paint directly onto OSB board?

Do you need to prime OSB board? If you want to paint directly onto OSB board, buy extra paint.

OSB is porous and it will absorb a lot of paint, so you will need two or three coats, possibly more, to get full color coverage. As OSB ages, it becomes even more porous and even more difficult to paint if you want to apply paint directly to the board.

Your best bet is to start with primer. The OSB will still need more than one coat of primer, but the paint will stick much better to this than to the bare board.

Which side of OSB should you paint?

One side of OSB will often be smoother than the other. If you're only painting one side of the board, this smoother side is the one that will be easier to paint.

You can paint the rough side of oriented strand board if you really want to, but start out with a few coats of primer before you apply the paint because this will make the paint stick better.

What is the best paint sealer for OSB?

Any water-resistant clear sealant designed for wood or particle board will work well on OSB. There are several types of paint sealers that are designed for MDF that will work just as well as oriented strand board.

To apply sealant, you paint it on in the same fashion that you would apply any paint or stain.

Will painting OSB make it waterproof?

Any paint will add a certain amount of water resistance to OSB because the water tends to roll off paint rather than being absorbed by it. Adding primer and sealant adds even more waterproofing protection to the board.

You can also select paint that is waterproof or a sealant that is waterproof to ensure that your OSB is weather-resistant and ready for the elements.