Can Flex Seal be used on Wood?

Wondering if Flex seal be used on wood? You’ve landed on the right page.

In the realm of home repairs and DIY projects, Flex Seal has emerged as a go-to solution for dealing with leaks and cracks in wooden surfaces. Its versatility and ease of application have made it popular among homeowners looking for quick fixes. However, with wood being a common material in construction and home projects, many wonder if Flex Seal is compatible with it. This article aims to shed light on the effectiveness of Flex Seal on wood surfaces, exploring its application, benefits, and any limitations.

Can flex seal be used on wood

Yes, Flex Seal can be used on wood. Flex Seal is a liquid rubber sealant coating that’s designed to be versatile and easy to use on a variety of materials, including wood, metal, glass, rubber, and more. When applied to wood, Flex Seal can provide a waterproof barrier that protects against moisture, air, and water. This makes it a suitable option for sealing leaks, cracks, and gaps in wooden surfaces.

Benefits of Using Flex Seal on Wood:

  • Waterproofing: Creates a waterproof seal that protects wood from moisture and water damage.
  • Flexibility: Flex Seal remains flexible after drying, which helps it resist cracking and breaking under movement or temperature changes.
  • Ease of Use: It can be easily applied with a spray can, brush, or roller, depending on the product form.
  • Versatility: Suitable for various applications, including outdoor furniture, wooden structures, and other wood projects exposed to moisture.

How to Apply Flex Seal on Wood:

  1. Prepare the Surface: Ensure the wood surface is clean, dry, and free of any dirt, grease, or loose paint. Sanding the surface lightly can help improve adhesion.
  2. Apply Flex Seal: Shake the can well if using Flex Seal in a spray form. Apply the sealant evenly over the area, covering it completely. For larger areas or for a more controlled application, Flex Seal Liquid can be applied with a brush or roller.
  3. Allow to Dry: Let the first coat dry completely. Flex Seal typically dries to the touch within 2 to 3 hours, but drying times can vary based on temperature and humidity. For best results, apply multiple coats, allowing each coat to dry before applying the next.
  4. Cure Time: Flex Seal fully cures in 24 to 48 hours, depending on the application thickness and environmental conditions.


  • Aesthetics: Flex Seal dries to a rubbery, somewhat glossy finish that might not be suitable for all wood projects, especially where the natural look of the wood is desired.
  • Application Thickness: Thick applications may require longer drying and curing times.
  • Indoor Use: Ensure adequate ventilation if applying Flex Seal indoors due to the fumes.

Flex Seal can be a practical solution for waterproofing and protecting wood, especially in applications where the appearance of the final product is not the primary concern. It’s important to follow the manufacturer’s instructions for the best results.

Types of flex seal products that work on wood:

Flex Seal offers a range of products suitable for sealing and protecting wood from moisture and damage. Each product in their lineup has unique application methods and benefits, making them versatile for different types of projects involving wood. Here are the primary Flex Seal products that work well on wood:

1. Flex Seal Spray

  • Description: A liquid rubber sealant coating that comes in an aerosol spray can. It’s easy to use and applies evenly to cover leaks, cracks, and holes on various surfaces.
  • Best For: Quick fixes and hard-to-reach areas, sealing around joints and small cracks, and projects where a brushable application is impractical.

2. Flex Seal Liquid

  • Description: A liquid rubber sealant that can be brushed, rolled, dipped, or poured onto surfaces, offering more control over the application thickness.
  • Best For: Larger surface areas, projects requiring a thicker coating, or when a dipped finish is desired. Ideal for waterproofing wooden planters, furniture, and decks.

3. Flex Shot

  • Description: A thick rubber sealant that comes in a caulk-like tube, designed for precise application. It’s used to fill larger cracks and holes without the need for a caulking gun.
  • Best For: Sealing joints and larger cracks where more precision is required, such as wooden window frames and doorways.

4. Flex Tape

  • Description: A super strong, waterproof tape that can patch, bond, seal, and repair virtually anything. It’s specially formulated with a thick, flexible, rubberized backing.
  • Best For: Emergency repairs and patching up holes or leaks on wooden surfaces quickly. Suitable for temporary fixes on wooden boats, furniture, and outdoor equipment.

5. Flex Glue

  • Description: A strong, rubberized, waterproof adhesive that can bond, seal, or repair almost everything. It can be applied to wet or dry surfaces and even underwater.
  • Best For: Projects requiring strong adhesion in addition to sealing, such as attaching wooden pieces together or sealing gaps while also bonding objects.

6. Flex Paste

  • Description: A thick paste that can be used to fill gaps, cracks, and holes. It dries to a strong, flexible, rubberized coating.
  • Best For: Filling larger holes and gaps in wood, sealing up openings in wooden structures, and creating a waterproof barrier where a paste application is ideal.

Application Tips for Wood:

  • Surface Preparation: For all Flex Seal products, ensure the wood surface is clean, dry, and free of grease, oil, and dirt for the best adhesion.
  • Testing: It’s a good idea to test the product on a small, inconspicuous area first to ensure it meets your expectations for appearance and performance.
  • Multiple Coats: Applying multiple thin coats, rather than one thick coat, often yields better results, especially for sprays and liquids. Allow each coat to dry thoroughly before applying the next.
  • Curing Time: Allow the product to fully cure as per the instructions on the package before exposing the wood to moisture or stress.

Choosing the right Flex Seal product for your wood project depends on the specific needs of the project, including the size of the area to be sealed, the type of wood, and the environmental conditions it will be exposed to.

How To Seal a Wood Fence With Flex Seal Liquid
Sealing a wood fence with Flex Seal Liquid is a practical way to protect it from moisture, rot, and decay while extending its lifespan. Flex Seal Liquid is a rubberized coating that can seal, coat, and protect almost any surface, including wood. Here’s how to apply Flex Seal Liquid to a wood fence:

Materials Needed

  • Flex Seal Liquid
  • Paintbrush, roller, or a paint sprayer (if applicable)
  • Sandpaper (optional, for prepping the surface)
  • Clean cloth or a tack cloth
  • Protective gloves
  • Safety glasses


  1. Clean the Fence: Ensure the fence is clean and free from dirt, grease, moss, and debris. Use a pressure washer or a stiff brush with soapy water to thoroughly clean the surface and allow it to dry completely.
  2. Sand the Surface (Optional): If the fence is rough, previously untreated, or if you’re applying over an old sealant or paint, lightly sand the surface with sandpaper. This step is to ensure a smooth surface for better adhesion of the Flex Seal Liquid.
  3. Remove Dust: After sanding, wipe down the fence with a clean cloth or a tack cloth to remove all dust and debris.


  1. Stir the Product: Before application, stir the Flex Seal Liquid thoroughly to ensure a uniform consistency. Do not shake.
  2. Apply Flex Seal Liquid: Using a paintbrush, roller, or a paint sprayer, apply Flex Seal Liquid evenly over the wood surface. For larger fences, a paint sprayer might be more efficient and provide a more uniform coat. Ensure to cover all surfaces, edges, and crevices thoroughly. See images on Flex Seal Products blog here.
  3. Thickness: Apply a generous amount, but avoid overly thick layers that might drip or sag. Flex Seal Liquid can be applied in multiple coats for better protection, but each coat should be allowed to dry completely before applying the next. Typically, a 24-hour dry time is recommended between coats, but this can vary based on humidity and temperature.
  4. Drying Time: Allow the Flex Seal Liquid to dry completely. Drying times can vary depending on the environment, but it usually takes about 24 to 48 hours for the surface to become dry to the touch. Full curing might take longer, so refer to the product instructions for specific details.

Aftercare and Maintenance

  • Check Regularly: Inspect the coating periodically for any signs of wear or damage, and reapply as necessary to maintain the protective layer.
  • Clean Gently: For maintenance cleaning, avoid abrasive tools that might damage the seal. Use a soft brush or cloth with soapy water.

Tips for Best Results

  • Weather Conditions: Apply Flex Seal Liquid on a dry, warm day with low humidity to ensure the best drying conditions.
  • Safety Precautions: Wear protective gloves and safety glasses during application. Ensure good ventilation if working in a confined space.
  • Test First: If you’re unsure about the finished look or adherence, test the Flex Seal Liquid on a small, inconspicuous area of the fence first.

Using Flex Seal Liquid on your wood fence can provide durable protection against the elements, helping to prevent water damage and extend the life of the fence. Always follow the product’s specific instructions for the best results.

How to use flex seal on wood decks:

Using Flex Seal on a wood deck can help protect it from water damage, leaks, and rot. Flex Seal products, particularly Flex Seal Liquid, are suitable for creating a waterproof barrier over wood surfaces. Here’s how to apply Flex Seal to a wood deck:

Materials Needed

  • Flex Seal Liquid (or Flex Seal Spray for smaller areas)
  • Paintbrush, roller, or a paint sprayer for larger decks
  • Sandpaper (if the deck needs smoothing)
  • Cleaning supplies (broom, garden hose, or pressure washer)
  • Protective gloves and safety glasses


  1. Clean the Deck: Start by thoroughly cleaning your deck to remove dirt, grime, loose wood fibers, and old sealants or stains that might prevent Flex Seal from adhering properly. Use a pressure washer on a low setting or scrub the deck with a deck cleaner and a stiff brush. Allow the deck to dry completely, which may take 24-48 hours depending on weather conditions.
  2. Repair Damages: Inspect the deck for any damaged areas, including loose boards, nails, or screws. Make necessary repairs to ensure a smooth and stable surface for the Flex Seal application.
  3. Sand the Surface (Optional): If the wood is rough or splintered, lightly sand the surface with sandpaper to achieve a smooth finish. This step is particularly important for areas that will be in direct contact with people, such as railings and seating areas. After sanding, clean off the sawdust.


  1. Apply Flex Seal Liquid: Stir the Flex Seal Liquid thoroughly before use. Using a paintbrush, roller, or a paint sprayer, apply Flex Seal evenly over the deck’s surface. Ensure all areas, including seams and joints, are well covered. For a paint sprayer, follow the manufacturer’s instructions to thin the Flex Seal Liquid if necessary.
  2. Apply Multiple Coats: For best results and a more durable finish, apply multiple thin coats rather than a single thick coat. Allow each coat to dry completely (at least 24 hours) before applying the next. The number of coats needed may vary depending on your deck’s condition and the level of protection you desire.
  3. Drying Time: Flex Seal Liquid typically dries to the touch within 2 to 3 hours, but it requires 24 to 48 hours to fully cure. Allow ample drying time before using the deck or placing furniture on it. Curing times can vary based on temperature, humidity, and ventilation.

Aftercare and Maintenance

  • Regular Inspection: Check the sealed deck periodically for any signs of wear or damage. Areas with heavy foot traffic may need more frequent reapplication.
  • Cleaning: Clean the deck regularly with mild soap and water to maintain its appearance and prevent buildup of dirt and debris.

Tips for Best Results

  • Weather Conditions: Apply Flex Seal during dry weather with moderate temperatures to ensure proper drying and curing.
  • Safety Precautions: Wear protective gloves and safety glasses during application. Ensure good ventilation if applying Flex Seal in enclosed spaces.
  • Test First: Before applying Flex Seal to the entire deck, test it on a small, inconspicuous area to ensure it provides the desired appearance and compatibility with the wood.

Flex Seal can offer an effective waterproof barrier for wood decks, but it’s important to follow these steps carefully to ensure the best protection and longevity of your deck. Always refer to the product’s specific instructions for additional guidance and safety information.


Q: Can I use Flex Seal Liquid on a painted or stained deck?

A: Yes, as long as the paint or stain is fully cured and dry before applying Flex Seal.

Q: How often do I need to reapply Flex Seal on my deck?

A: It depends on the amount of wear and tear your deck experiences, but it’s recommended to inspect and potentially reapply every 1-2 years for best results.

Q: Can I use Flex Seal on a composite or PVC deck?

A: No, Flex Seal is not recommended for use on these materials as they do not have the same absorbent properties as wood.

Q: Is Flex Seal safe for plants and animals once it has dried?

A: Yes, once fully dried and cured, Flex Seal is safe for plants and animals. However, it is always recommended to keep pets and children away from the area during application.

Q: Can I use a pressure washer to clean my deck after applying Flex Seal?

A: Yes, you can use a pressure washer on your deck once Flex Seal has fully cured. However, avoid using high pressure and keep the nozzle at least 12 inches away from the surface to prevent any damage.

Q: Is it necessary to use a primer before applying Flex Seal on my deck?

A: No, Flex Seal does not require a primer. However, if your wood is prone to rot or decay, it is recommended to use a wood preservative before applying Flex Seal for added protection.

Q: What should I do if I accidentally spill Flex Seal on my skin or clothing?

A: If Flex Seal comes into contact with skin, wash the area with soap and water immediately. For clothing, let the product dry completely before attempting to remove it. Once dried, use a dull knife or credit card to scrape off as much of the product as possible, then wash the clothing as usual.

Q: Can Flex Seal be used on horizontal surfaces?

A: Yes, Flex Seal can be used on both horizontal and vertical surfaces. It is important to follow the instructions for proper application and allow it to dry completely before use.

Wrapping up:

In conclusion, Flex Seal offers a versatile and effective solution for wood sealing and protecting various surfaces. Its application on both horizontal and vertical wood surfaces, combined with its safety for plants and animals once cured, makes it a reliable choice for many home repair and maintenance tasks. Although it requires certain precautions during application, such as keeping pets and children at a distance and avoiding direct pressure on newly coated surfaces, its ease of use without the need for a primer on most surfaces simplifies the process. Additionally, its compatibility with pressure washers, once fully cured, and straightforward cleanup procedures for accidental spills, further enhance its practicality for DIY enthusiasts and professionals alike.