How To Make an OSB Board Waterproof? [Procedure & Precautions]
Wondering how to keep your newly purchased OSB board dry before and after installation? Although wood particles pressed together can build OSB boards, young strands of wood mixed with resin can also create flexible and stiff OSD boards.
While most of these boards are often waterproofed before leaving the store, they can still get wet, as indicated on the back. In this article, we’ll show you how to make OSB boards waterproof.
The boards’ surfaces often repel water, but the edges rarely do; they are a bit more vulnerable.
When too wet, OSB can swell irreversibly, mainly at the edges. It is essential to know that while OSB is not too sensitive to a few drops of water, it gradually absorbs the water, and drying out is relatively slow.
What Happens If the OSB Board Gets Wet?
- OSD boards degrade more than plywood if repeatedly exposed to moisture.
- Swelling occurs when these engineered wood boards absorb a lot of moisture in contact with water or air. While they don’t cause leaks, they are known to trigger rot or fungal growth.
- OSB gradually absorbs water, but when it does, it may take a while for it to dry before all of the moisture dries up. The Slow drying rate can cause the interiors of the liner to rot, eventually affecting neighboring boards.
- Wet OSBs can promote fungal growth because of the mold spores they already have in them. Minimal exposure to moisture still can foster fungal growth that starts from inside.
How To Make an OSB Board Waterproof?
Waterproofing OSB boards provide better moisture resistance and even reduce the risk of damage in the event of a fire, especially when exposed to extreme conditions. You can waterproof your OSD wood with the following approaches:
- Using Paint
- Using Sealer and vinyl siding
How To Make an OSB Board Using Paint?
Not only does good quality exterior paint significantly increase the water-resistance of your OSB, but it also adds a pop color to your board.
If you’re wondering which paint to use, then oil or latex paints are the best choices—just painting the OSB as you would plywood leaves the OSB more uneven than before.
In addition, the paint will slide through the primer while still using the water-based paint, which causes OSB to peel over time, making it very unattractive and highly unappealing, and frequently requiring maintenance.
If you intend to use your OSB boards indoors, an acrylic latex primer will be a suitable base since it’s pretty easy to use. Additionally, Latex primers dry quickly, so they take under an hour to dry. They are almost odorless, and they rarely contribute to air pollution.
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Required Material:
- Oil-based paint or Latex paint
- Paintbrush.
- Measuring tape
- Saw
- Primer
- Roller
Procedure [Step by Step]
- With the help of a tape measure, mark the required width and length of the board then carefully cut using a saw.
- Apply a water resistant primer since OSD has a lot of pores.
- Dip the brush tip into the paint and begin brushing it on the surface and the edges.
- Ensure to repeat the process on both sides, not only where you previously made the cuts.
- Coat the parts while they are on the sheet, then allow the waterproofer to dry for about 2 hours.
- Gently turn the board over and paint the remaining surfaces. You’re more likely to need more than just a coat of waterproofing to protect the wood.
- Allow the solution to dry for an additional 2 hours between coats. If you live in a humid area, the drying period can be longer.
Duration:
The whole process would l take a maximum of 8 hours
Precautions:
Ensure the work area is well ventilated to avoid the accumulation of flammable vapors. This minimizes the risk of explosion and fire. Since paint is considered volatile, ensure you have enough ventilation and no ignition sources.
How To Make an OSB Board Waterproof Using Sealer, House Wrap, and Vinyl Siding?
The outside walls of your vinyl-covered home are made up of layers of various materials created to ensure your home is dry and, warm when there’s winter.
The frame is covered on the outside with an oriented board (OSB). OSB consists of strands of resin-coated wood pressed together into planks in a heat press.
Before installing the vinyl siding on the house, a waterproof underlay known as a house wrap should first be placed over the OSB board to protect the board from water that seeps through the siding and reaches the board.
A house wrap is a breathable membrane but it’s not waterproof. A sealer on the other hand is a special kind of primer mainly to be used with or instead of a primer.
A sealer prevents the finish from penetrating the substrate, and to some extent, it creates a water-resistant layer between the finish and the substrate.
Required Material:
- Vinyl siding kit
- Paintbrush
- Measuring tape
- Saw
- Roller
- Sealer
- Sandpaper
- A large container
- Hammer and nails
- House wrap
- Primer
Procedure [Step by Step]
- Using sandpaper, lightly rub the OSD’s surface. Avoid sanding the edges.
- Clean the board’s surface thoroughly. Due to the rough structure of OSB, non-stick cloth and cotton cloths are less likely to work well. Instead, a vacuum cleans the surface.
- With gloves on, empty the primer into a container; spread it carefully on the platter after dipping the roller.
- Apply a second coat of primer to the OSB by making W-shaped passes over the board. Don’t apply a thick coat.
- Allow it to sit for at least two hours, then add another coat. Do this repeatedly until the board flake is no longer visible.
- If you want exceptionally smooth edges and surfaces, apply a layer of resin sealant gently using a spatula. Smooth the edges with sandpaper. Repeat this cycle several times until you notice that the texture is smooth.
- If you have applied the sealant and it is smooth to your satisfaction, refill it twice.
- Place a house wrap and fix it to using a hammer and nails.
- Now you can carefully install the vinyl siding to the edges to cover the edges.
Duration:
The whole process would take a maximum of 9 hours
Precautions:
- We recommend that you wear protective gloves and clothing to prevent the sealant from contacting the skin. When this happens, the skin may experience mild to very severe irritation. Wash off the sealant immediately in case of accidental contact to avoid, if possible, problems from occurring
- If possible, avoid water-based sealers as OSB boards will swell on contact with water or moisture
In this article, we have explained how to make your OSD board waterproof. The two best approaches are vinyl siding which we highly recommend for OSD boards outdoors to keep them from being damaged by rain.
The other approach is waterproof paint suitable for OSD boards inside the house as it waterproofs the board and adds a pop of color to it.
