How To Seal Plywood For Exterior Use

Table of Contents

Sealing plywood is an important part of many woodworking and construction projects. If you’re going to be using plywood outdoors, or in any other environment where it might be exposed to moisture, you need to make sure that it’s properly sealed. Otherwise, the plywood could start to rot and deteriorate.

There are a few different ways that you can seal plywood, and the method that you choose will depend on the project that you’re working on. If you’re just looking to seal the edges of the plywood, you can use a product like edge banding. Edge banding is a strip of material that you attach to the edges of the plywood, and it will help to seal them against moisture.

You can also seal the entire surface of the plywood with a product like polyurethane. To seal with polyurethane, you’ll need to apply a few coats to the surface of the plywood, allowing each coat to dry before applying the next.

What Is Seal Plywood?

Seal plywood refers to the process of protecting the surface of the plywood from moisture, weather, and other elements that can cause damage. This protection helps to prevent the plywood from warping, rotting, or splitting and extends its lifespan. Sealing plywood can also improve its overall appearance by providing a smooth, uniform surface.

Reasons Why You Need to Seal Plywood for Exterior Use

Plywood is a durable building material, but without proper protection, it can quickly deteriorate when exposed to the elements. Here are six reasons why you need to seal your plywood for outdoor use:

Protects against moisture damage: Moisture is one of the biggest enemies of plywood. When exposed to moisture, the plywood can warp, rot, and split, causing significant damage. Sealing the plywood helps to prevent moisture from seeping into the surface and causing damage.

Prevents UV damage: Sunlight can cause the color of your plywood to fade and eventually crack. Sealing the plywood helps to protect the surface from harmful UV rays, preserving its color and preventing cracking.

Increases durability: Plywood can be brittle and easily damaged by impacts and other external forces. Sealing the plywood helps to reinforce the surface, making it stronger and more durable.

Improves appearance: Sealing the plywood provides a smooth, uniform surface, making it look better and more attractive.

Increases resistance to insects: Certain types of insects, such as termites and beetles, can cause significant damage to plywood. Sealing the plywood helps to prevent these insects from accessing the surface, keeping your plywood protected.

Extends lifespan: By protecting the plywood from the elements, sealing it helps to extend its lifespan, ensuring that you get the most out of your investment.

Importance of Sealing Plywood for Exterior Use

Sealing plywood for exterior use is important for several reasons, including:

Protection from moisture: Sealing plywood helps to protect it from moisture damage, which can cause the wood to rot and deteriorate over time.

Protection from UV damage: Sealing plywood helps to protect it from UV damage, which can cause the wood to fade and crack over time.

Extended lifespan: Sealing plywood can extend the lifespan of the wood and help it to last longer when used outdoors.

Improved appearance: Sealing plywood can improve its appearance and help it to look its best for a longer period of time.

Increased durability: Sealing plywood can make it more durable and resistant to damage, helping it to hold up better over time.

Ease of maintenance: Sealing plywood can make it easier to maintain and clean, helping it to look its best with less effort.

Related Post: What is Plywood Used For?

Various Types of Sealants

Garden Box Sealer | FDA Food Contact Safe Plant-Based Wood Sealant for Raised Beds, Planters & Pet Houses. Protects All Wood Types from Water & Weather Damage | Eco-Friendly Sustainable Solution
Seal-Once Marine Premium Wood Sealer - Waterproof Sealant - Wood Stain and Sealer in One - 1 Gallon & Clear
Seal-Once Nano+Poly Penetrating Wood Sealer with Polyurethane - Premium Waterproof Sealant -1 Gallon & Clear
Roxil Wood Waterproofing Sealer (1.3 Gallon Clear) 10 Year Outdoor Wood Treatment, Wood Preserver for Decking, Fence, Sheds and Furniture
Rain Guard Water Sealers - Wood Sealer - Penetrating Water Repellent Protection for All Porous Wood Surfaces - Water-Based Silane/Siloxane Sealant - Clear Natural Finish - Ready to Use - 16oz Spray
Minwax 233334444 Polycrylic Protective Wood Finish, Clear Satin, ½ Pint
Garden Box Sealer | FDA Food Contact Safe Plant-Based Wood Sealant for Raised Beds, Planters & Pet Houses. Protects All Wood Types from Water & Weather Damage | Eco-Friendly Sustainable Solution
Seal-Once Marine Premium Wood Sealer - Waterproof Sealant - Wood Stain and Sealer in One - 1 Gallon & Clear
Seal-Once Nano+Poly Penetrating Wood Sealer with Polyurethane - Premium Waterproof Sealant -1 Gallon & Clear
Roxil Wood Waterproofing Sealer (1.3 Gallon Clear) 10 Year Outdoor Wood Treatment, Wood Preserver for Decking, Fence, Sheds and Furniture
Rain Guard Water Sealers - Wood Sealer - Penetrating Water Repellent Protection for All Porous Wood Surfaces - Water-Based Silane/Siloxane Sealant - Clear Natural Finish - Ready to Use - 16oz Spray
Minwax 233334444 Polycrylic Protective Wood Finish, Clear Satin, ½ Pint
$94.17
$68.98
$63.98
$29.99
$16.98
$12.98
Garden Box Sealer | FDA Food Contact Safe Plant-Based Wood Sealant for Raised Beds, Planters & Pet Houses. Protects All Wood Types from Water & Weather Damage | Eco-Friendly Sustainable Solution
Garden Box Sealer | FDA Food Contact Safe Plant-Based Wood Sealant for Raised Beds, Planters & Pet Houses. Protects All Wood Types from Water & Weather Damage | Eco-Friendly Sustainable Solution
$94.17
Seal-Once Marine Premium Wood Sealer - Waterproof Sealant - Wood Stain and Sealer in One - 1 Gallon & Clear
Seal-Once Marine Premium Wood Sealer - Waterproof Sealant - Wood Stain and Sealer in One - 1 Gallon & Clear
$68.98
Seal-Once Nano+Poly Penetrating Wood Sealer with Polyurethane - Premium Waterproof Sealant -1 Gallon & Clear
Seal-Once Nano+Poly Penetrating Wood Sealer with Polyurethane - Premium Waterproof Sealant -1 Gallon & Clear
$63.98
Roxil Wood Waterproofing Sealer (1.3 Gallon Clear) 10 Year Outdoor Wood Treatment, Wood Preserver for Decking, Fence, Sheds and Furniture
Roxil Wood Waterproofing Sealer (1.3 Gallon Clear) 10 Year Outdoor Wood Treatment, Wood Preserver for Decking, Fence, Sheds and Furniture
$29.99
Rain Guard Water Sealers - Wood Sealer - Penetrating Water Repellent Protection for All Porous Wood Surfaces - Water-Based Silane/Siloxane Sealant - Clear Natural Finish - Ready to Use - 16oz Spray
Rain Guard Water Sealers - Wood Sealer - Penetrating Water Repellent Protection for All Porous Wood Surfaces - Water-Based Silane/Siloxane Sealant - Clear Natural Finish - Ready to Use - 16oz Spray
$16.98
Minwax 233334444 Polycrylic Protective Wood Finish, Clear Satin, ½ Pint
Minwax 233334444 Polycrylic Protective Wood Finish, Clear Satin, ½ Pint
$12.98

When it comes to sealing plywood, there are a variety of different sealants available to choose from. The most common types of sealants include:

Oil-based sealers: These sealers are made from petroleum products and are ideal for outdoor use. They provide a strong, durable seal that is resistant to moisture and UV damage. However, they do have a strong odor and take longer to dry than other types of sealers.

Water-based sealers: These sealers are made from a water-soluble resin and are ideal for outdoor use. They are easy to apply, have a low odor, and dry quickly. However, they may not be as durable as oil-based sealers and may require reapplication more frequently.

Polyurethane sealers: These sealers are made from a synthetic polymer and are ideal for outdoor use. They are highly durable and provide a strong, water-resistant seal. However, they can be more expensive than other types of sealers and may require more maintenance to keep them looking their best.

Acrylic sealers: These sealers are made from a water-soluble resin and are ideal for outdoor use. They are easy to apply, have a low odor, and dry quickly. However, they may not be as durable as polyurethane sealers and may require reapplication more frequently.

Silicone sealers: These sealers are made from a silicone-based compound and are ideal for outdoor use. They are highly flexible and provide a strong, water-resistant seal. However, they can be more expensive than other types of sealers and may not adhere as well to certain types of surfaces.

Factors To Consider When Choosing the Best Sealant for Plywood

When choosing a sealant for your plywood, there are several factors to consider to ensure you choose the right product for your needs. These factors include:

Durability: Consider how long you want the sealant to last and how much maintenance you are willing to perform. Oil-based sealers tend to be the most durable, while water-based sealers may require more frequent reapplication.

Water resistance: Consider how much water the plywood will be exposed to and choose a sealant that provides a strong, water-resistant seal. Silicone sealers tend to be the most water-resistant, while water-based sealers may not provide as much protection.

UV resistance: Consider how much sunlight the plywood will be exposed to and choose a sealant that provides protection from UV damage. Oil-based sealers tend to be the most UV-resistant, while water-based sealers may not provide as much protection.

Ease of application: Consider how easy you want the sealing process to be and choose a sealant that is easy to apply and dries quickly. Water-based sealers tend to be the easiest to apply, while oil-based sealers may take longer to dry.

Cost: Consider how much you are willing to spend on the sealing process and choose a sealant that fits within your budget. Oil-based sealers tend to be the most expensive, while water-based sealers may be more budget-friendly.

Related Post: What is OSB plywood?

How To Seal Plywood for Exterior Use

Tools Needed to Seal Plywood for Exterior Use

Sealing plywood is a straightforward process, but it does require a few specific tools to get the job done right. The following tools will come in handy when sealing your plywood:

Pro Grade - Paint Brushes - 12Ea 2" Angle Brushes
Benchmark Abrasives 6" PSA Gold Self Adhesive DA Sanding Disc Roll Aluminum Oxide Grains Designed for Surface Blending Edge Sanding General Stock Removal Orbital Sanders (100 Discs) - 320 Grit
Stormdry Brick Sealer - Clear Brick, Stone, Concrete & Masonry Waterproofer - 25-Year Certified Waterproofing Protection Against Penetrating Damp - 1.5 Gallon
Graco 17D163 Pro210ES Stand Airless Paint Sprayer
S&F STEAD & FAST Tack Cloth Automotive, 30 pcs, Bulk 2-Box Auto Sticky Tac Cloths Set, Premium Professional Grade Tack Rags for Woodworking, Painting, Sanding
The Army Painter Complete Airbrush Paint Set and Airbrush Thinner - Air Brush Painting Set, Airbrush Painting Supplies, Warpaints Air Brush Paint Acrylic, Airbrush Kit
Pro Grade - Paint Brushes - 12Ea 2" Angle Brushes
Benchmark Abrasives 6" PSA Gold Self Adhesive DA Sanding Disc Roll Aluminum Oxide Grains Designed for Surface Blending Edge Sanding General Stock Removal Orbital Sanders (100 Discs) - 320 Grit
Stormdry Brick Sealer - Clear Brick, Stone, Concrete & Masonry Waterproofer - 25-Year Certified Waterproofing Protection Against Penetrating Damp - 1.5 Gallon
Graco 17D163 Pro210ES Stand Airless Paint Sprayer
S&F STEAD & FAST Tack Cloth Automotive, 30 pcs, Bulk 2-Box Auto Sticky Tac Cloths Set, Premium Professional Grade Tack Rags for Woodworking, Painting, Sanding
The Army Painter Complete Airbrush Paint Set and Airbrush Thinner - Air Brush Painting Set, Airbrush Painting Supplies, Warpaints Air Brush Paint Acrylic, Airbrush Kit
$29.99
$38.99
$149.99
$967.34
$26.99
$277.57
Pro Grade - Paint Brushes - 12Ea 2" Angle Brushes
Pro Grade - Paint Brushes - 12Ea 2" Angle Brushes
$29.99
Benchmark Abrasives 6" PSA Gold Self Adhesive DA Sanding Disc Roll Aluminum Oxide Grains Designed for Surface Blending Edge Sanding General Stock Removal Orbital Sanders (100 Discs) - 320 Grit
Benchmark Abrasives 6" PSA Gold Self Adhesive DA Sanding Disc Roll Aluminum Oxide Grains Designed for Surface Blending Edge Sanding General Stock Removal Orbital Sanders (100 Discs) - 320 Grit
$38.99
Stormdry Brick Sealer - Clear Brick, Stone, Concrete & Masonry Waterproofer - 25-Year Certified Waterproofing Protection Against Penetrating Damp - 1.5 Gallon
Stormdry Brick Sealer - Clear Brick, Stone, Concrete & Masonry Waterproofer - 25-Year Certified Waterproofing Protection Against Penetrating Damp - 1.5 Gallon
$149.99
Graco 17D163 Pro210ES Stand Airless Paint Sprayer
Graco 17D163 Pro210ES Stand Airless Paint Sprayer
$967.34
S&F STEAD & FAST Tack Cloth Automotive, 30 pcs, Bulk 2-Box Auto Sticky Tac Cloths Set, Premium Professional Grade Tack Rags for Woodworking, Painting, Sanding
S&F STEAD & FAST Tack Cloth Automotive, 30 pcs, Bulk 2-Box Auto Sticky Tac Cloths Set, Premium Professional Grade Tack Rags for Woodworking, Painting, Sanding
$26.99
The Army Painter Complete Airbrush Paint Set and Airbrush Thinner - Air Brush Painting Set, Airbrush Painting Supplies, Warpaints Air Brush Paint Acrylic, Airbrush Kit
The Army Painter Complete Airbrush Paint Set and Airbrush Thinner - Air Brush Painting Set, Airbrush Painting Supplies, Warpaints Air Brush Paint Acrylic, Airbrush Kit
$277.57

Steps:

Clean the Plywood

Before sealing your plywood for outdoor use, it’s important to clean it thoroughly to remove any dirt, grime, or other debris that may have accumulated on its surface. This can be done with a combination of soap, water, and a stiff-bristled brush. Scrub the plywood well, paying extra attention to areas that are particularly dirty or stained. Once you’re finished cleaning, allow the plywood to dry completely before moving on to the next step.

Sand the Plywood

Once your plywood is clean and dry, it’s time to sand it. Sanding helps to smooth out any rough or uneven areas, which will make it easier to apply the sealant evenly. You should use a fine-grit sandpaper, such as 220-grit, to avoid damaging the surface of the plywood. Start sanding in the same direction as the grain, using long, smooth strokes. After sanding, use a clean, dry cloth to remove any sawdust or debris that may have accumulated on the surface.

Apply the Sealant

Now that your plywood is clean and sanded, it’s time to apply the sealant. Start by selecting a sealant that’s appropriate for your needs, based on the type of plywood you’re using, the environment it will be exposed to, and any other factors that may be relevant. Read the manufacturer’s instructions carefully and follow them closely. Apply the sealant using a paintbrush or roller, starting in one corner of the plywood and working your way across, being sure to cover every inch of the surface. Apply the sealant evenly and thinly, taking care not to leave any drips or runs.

Allow Drying Time

After you’ve applied the sealant, allow it to dry completely according to the manufacturer’s instructions. This usually takes anywhere from a few hours to a full day, depending on the type of sealant you’re using and the conditions in your area.

Sand Between Coats

After the first coat of sealant has dried, it’s a good idea to sand the surface lightly with a fine-grit sandpaper. This will help to smooth out any rough or uneven areas and ensure that the second coat of sealant adheres well to the surface. Be sure to remove any sawdust or debris from the surface after sanding.

Apply Additional Coats as Needed

Depending on the type of sealant you’re using, the environment that your plywood will be exposed to, and the condition of the plywood itself, you may need to apply additional coats of sealant. Repeat the process of applying, allowing to dry, and sanding between coats until you’ve reached the desired level of protection and durability.

Allow Final Coat to Dry

Once you’ve applied the final coat of sealant, allow it to dry completely according to the manufacturer’s instructions.

Inspect for Any Missed Areas

Once the final coat of sealant has dried, inspect the surface of the plywood for any missed areas. If you find any areas that haven’t been fully covered, simply apply another thin coat of sealant to those areas, being sure to allow it to dry completely before moving on.

Related Post: How To Seal Plywood Edges: Guide and Checklist

How To Maintain Sealed Plywood for Exterior Use

Maintaining your plywood and sealant is very important for protecting the longevity of your exterior.

Clean Regularly

One of the key ways to maintain a sealed plywood surface is to clean it regularly. This means removing any dirt, debris, or other buildup that may have accumulated on the surface. Regular cleaning will not only help keep the surface looking great, but it will also help preserve the integrity of the sealant and protect against water damage.

Reapply Sealant Every 2-3 Years

Another important step in maintaining a sealed plywood surface is to reapply the sealant every 2-3 years. This will ensure that the surface remains protected from the elements, including moisture and UV damage. To reapply the sealant, simply follow the steps outlined in the earlier sections on sealing plywood, making sure to properly clean and sand the surface before applying the new sealant.

Keep Plywood Out of Direct Sunlight

Another way to protect a sealed plywood surface is to keep it out of direct sunlight as much as possible. This will help prevent the sealant from breaking down due to exposure to UV rays, and will also help keep the surface looking great for years to come.

Inspect for Any Damage Regularly

Regular inspection of a sealed plywood surface is also important, as this will help you catch any damage early and take action to repair it before it becomes a larger problem. Check the surface for any cracks, chips, or other signs of damage, and address any issues you find promptly.

Repair Any Damage Promptly

If you do find any damage to a sealed plywood surface, it is important to repair it promptly. This will help prevent further damage, protect the integrity of the sealant, and ensure that the surface continues to look great for years to come.

Store Properly When Not in Use

It is important to store sealed plywood properly when it is not in use. This will help protect the surface from damage and preserve the integrity of the sealant, ensuring that it is ready to use whenever you need it.

Safety Precautions: How To Seal Wood for Exterior Use

Wear Proper Safety Equipment

Wearing proper safety equipment is a critical aspect of sealing wood for exterior use. This includes gloves, a face mask, eye protection, and clothing that covers your arms and legs. Wearing gloves will protect your hands from coming into direct contact with the sealant, which can be harmful if it gets on your skin. A face mask and eye protection are important for preventing inhalation of fumes, which can be harmful to your respiratory system. Wearing long sleeves and pants will protect your skin from coming into contact with the sealant and also helps keep your clothes clean.

It’s important to take safety precautions when sealing wood for exterior use, as the process can expose you to a number of hazardous chemicals. By wearing the proper safety equipment, you can help to protect yourself from these potential health risks and ensure that you’re able to complete the job safely and effectively.

Work in a Well-Ventilated Area

Another important safety precaution when sealing wood for exterior use is to work in a well-ventilated area. This helps to prevent the build-up of fumes from the sealant, which can be harmful if inhaled. When working with sealant, it’s best to do so outside or in a garage with the door open, or in a room with open windows and a fan to circulate the air. If you’re working indoors, be sure to turn off any air conditioning or heating systems that could recirculate the fumes.

Working in a well-ventilated area is critical to your safety when sealing wood for exterior use, as it helps to reduce the risk of inhaling harmful fumes. By taking this simple step, you can help to protect your respiratory system and ensure that you’re able to complete the job safely and effectively.

Follow Manufacturer’s Instructions

When sealing wood for exterior use, it’s important to follow the manufacturer’s instructions carefully. These instructions will provide important information about the product, including how to apply it, how many coats are needed, and how long to allow each coat to dry. By following the manufacturer’s instructions, you can help to ensure that you’re using the product correctly and that you’re getting the best possible results.

It’s also important to follow the manufacturer’s instructions for any safety precautions that are specific to their product, such as the need for protective clothing or the use of a respirator. By doing so, you can help to ensure that you’re using the product safely and effectively, and that you’re getting the best possible results.

Store Sealants Safely

When storing sealants, it is important to store them safely to minimize the risk of harm to yourself or others. This includes storing them in a cool, dry place, away from heat sources and flames, and making sure that the lids are securely fastened.

Avoid Contact with Skin and Eyes

It is important to avoid contact with skin and eyes when using sealants. If contact does occur, rinse the affected area thoroughly with water and seek medical attention if necessary.

Dispose of Any Leftover Sealant Properly

Finally, it is important to dispose of any leftover sealant properly, in accordance with local regulations and guidelines. Sealants often contain hazardous chemicals that can be harmful to both the environment and human health if not disposed of properly. To ensure that you’re disposing of your sealant safely, you should always follow the instructions provided by the manufacturer, which will outline the correct disposal methods for your specific product. Additionally, you can also check with your local waste management facility to see if they accept sealants and what their specific guidelines are.

How To Treat Plywood for Exterior Use

Sand the Plywood

Sanding the plywood before sealing it is important because it helps to remove any rough or raised edges, and provides a smooth surface for the sealant to adhere to. This will result in a better-looking finish, and ensure that the sealant lasts longer. It is recommended to use a fine-grit sandpaper, such as 220-grit, to avoid damaging the wood fibers.

Clean the Plywood

After sanding, it’s important to clean the plywood to remove any sawdust or debris. This will ensure that the primer and sealant adhere properly and provide a uniform finish. A clean cloth dampened with a mild soap and water solution can be used to clean the surface.

Apply Primer

Applying a primer to the plywood helps to create a uniform base for the sealant, and can also help prevent moisture from penetrating the wood. Primer should be applied evenly, in a thin coat, and allowed to dry according to the manufacturer’s instructions.

Apply Sealant

Once the primer has dried, the sealant can be applied. It is important to follow the manufacturer’s instructions for the specific product being used. Most sealants should be applied in thin, even coats, with sufficient drying time between coats. It is recommended to start at one end of the plywood and work towards the other end, to ensure complete coverage.

Sand Between Coats

Sanding between coats is important because it helps to create a smooth and uniform surface for the next coat of sealant to adhere to. It also helps to remove any rough or raised areas that may have formed after the previous coat was applied. It is recommended to use a fine-grit sandpaper, such as 220-grit, to avoid damaging the wood fibers.

Apply Additional Coats as Needed

The number of coats needed will depend on the type of sealant being used, and the desired level of protection. It is recommended to follow the manufacturer’s instructions for the specific product being used. If additional coats are needed, they should be applied in the same manner as the first coat, with sufficient drying time between coats.

FAQs: How To Seal Plywood for Outdoor Use

What is the Best Sealant for Exterior Plywood?

The best sealant for exterior plywood will depend on the specific conditions that the plywood will be exposed to, and the desired level of protection. Some common types of sealants for exterior use include acrylics, urethanes, and oil-based sealants. It is recommended to research and compare different products, and choose one that is specifically designed for exterior use and meets the specific needs of the project.

How Many Coats of Sealant Should I Apply to Plywood for Exterior Use?

The number of coats needed will depend on the type of sealant being used, and the desired level of protection. It is recommended to follow the manufacturer’s instructions for the specific product being used. Some products may require only one coat, while others may require multiple coats for optimal protection.

Can I Use Interior Sealant for Exterior Plywood?

No, it is not recommended to use interior sealant for exterior plywood. Interior sealants are designed for indoor use and may not be able to withstand the harsh weather conditions and UV exposure that exterior plywood is subjected to. It is recommended to use a sealant specifically designed for exterior use to ensure optimal protection.

How Often Should I Seal Plywood for Exterior Use?

The frequency with which plywood should be sealed will depend on several factors, such as the type of sealant being used, the weather conditions that the plywood is exposed to, and the level of wear and tear that the plywood experiences. It is typically recommended to reapply sealant every 2-3 years, or as needed based on the conditions and appearance of the plywood. Regular inspections for damage and prompt repairs can also help extend the life of the sealant and protect the plywood from damage.

Can I Paint Over Exterior Plywood Sealant?

Yes, you can paint over exterior plywood sealant. However, it is recommended to allow the sealant to fully cure before applying paint, as per the manufacturer’s instructions. Additionally, it may be necessary to lightly sand the surface of the plywood to provide a better surface for the paint to adhere to.

How Do I Remove Old Sealant from Exterior Plywood?

To remove old sealant from exterior plywood, you can use a paint stripper or sandpaper. If using a paint stripper, it is important to follow the manufacturer’s instructions and wear protective gear, such as gloves and goggles. If sanding, it is recommended to use a fine-grit sandpaper to avoid damaging the wood. Once the old sealant has been removed, the surface should be thoroughly cleaned and allowed to dry before applying a new coat of sealant.

Conclusion

Sealing plywood is an important part of protecting it from the elements. By taking the time to seal your plywood, you’ll extend its lifespan and keep it looking good for years to come. When applying the sealant, be sure to follow all safety precautions and always work in a well-ventilated area. Reapply the sealant every few years, or sooner if you notice any damage. If you have any questions, feel free to ask in the comments below. Thanks for reading.

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