Pitch, a sticky substance often exuded by trees, can be a frustrating challenge when it ends up on wooden deck boards. Not only can it create unsightly stains, but it can also make surfaces slippery and unpleasant to touch. Fortunately, with the right techniques and tools, removing pitch from wooden surfaces is a manageable task. This guide will provide you with simple, effective steps for how to clean pitch off wooden deck boards.
What Is Pitch and Why Does It Stick to Deck Boards?
Pitch is a naturally occurring resin secreted by certain types of trees, such as pines, firs, and spruces. It serves as a defense mechanism, helping to protect trees from pests and heal damage to their bark. This resin is highly sticky due to its chemical composition, which contains a combination of hydrocarbons and other organic compounds.
When deck boards are located near pitch-producing trees, the resin can drip or fall onto the wooden surface, especially during warmer months when it becomes more pliable. The adhesive nature of pitch makes it cling stubbornly to surfaces, creating both an aesthetic and practical challenge for deck maintenance.
Tools and Materials You’ll Need
To effectively remove tree pitch from your deck, you’ll need a few specific tools and cleaning agents. Here’s a list of items to gather before beginning the cleaning process:
- Plastic scraper or putty knife – For gently scraping off excess pitch without damaging the wood surface.
- Rubbing alcohol or mineral spirits – To break down the sticky resin and make it easier to remove.
- Soft cloths or rags – For applying cleaning solutions and wiping away residue.
- Mild soap and warm water – To clean the area after removing the pitch.
- Gloves – To protect your hands from irritants during the cleaning process.
- Bucket – For mixing and holding cleaning solutions.
- Sandpaper (optional) – For smoothing out any remaining residue or stubborn spots, if necessary.
Having these tools and materials on hand will ensure you’re prepared to tackle the pitch effectively while preserving the integrity of your deck.
10 Methods How to Clean Pitch off Wooden Deck Boards
1. Use Mineral Spirits for Mild Sap Spots
Mineral spirits offer a gentle yet effective approach to dissolving sap without causing harm to finished or unfinished deck wood. To use this method, dampen a clean rag or soft cloth with mineral spirits and gently rub the pitch spots in a circular motion. As the solvent breaks down the sap, wipe away the residue with a fresh part of the cloth. Always test in an inconspicuous spot first to check for color change or surface damage. Mineral spirits are ideal for light sap build-up and work best on sealed or stained decks.
2. Try Rubbing Alcohol or Isopropyl Alcohol
Rubbing alcohol is a readily available household item that’s surprisingly effective at removing sap. Simply soak a clean rag with isopropyl alcohol (at least 70%) and press it onto the pitch for 30–60 seconds to soften the residue. Then, rub the area until the sap lifts off. Alcohol evaporates quickly and doesn’t leave behind an oily film, making it suitable for decks where you plan to apply stain or sealant soon afterward. It’s an excellent solution for small spots or fresh sap before it has hardened.
3. Scrape Carefully with a Plastic Putty Knife
Sometimes, the best approach is also the simplest. If the pitch has hardened, you can carefully remove it with a plastic putty knife or similar non-metal scraper. Avoid using metal tools that might gouge or scar the wood fibers. Gently work the blade under the hardened sap and lift it away in layers. This method works well in combination with a solvent such as mineral spirits or alcohol, which you can apply before or after scraping to clean up any remaining residue.
4. Heat the Pitch with a Hair Dryer
Warmth helps soften pine pitch, making it easier to wipe away. Use a household hair dryer on a low or medium setting and direct the warm air at the sap spot for about 30–60 seconds. Once softened, wipe the area clean with a soft rag. This method is particularly useful in cooler weather or shaded areas where sap hardens more quickly. Avoid using heat guns, which are too hot and could scorch the wood or damage finishes. Combine with a mild solvent for best results.
5. Apply Commercial Deck Cleaners with Degreasers
There are many wood-safe commercial cleaners formulated specifically to handle organic stains, including sap, mildew, and grime. Look for products that list “sap” or “resin” as targets on the label. Apply according to the manufacturer’s instructions, usually with a brush or sprayer, and scrub the affected area with a stiff nylon brush. These cleaners are ideal for larger-scale cleaning or when sap is combined with dirt and debris. Always rinse thoroughly with water and allow the deck to dry completely before sealing or staining.
6. Use Olive Oil or Vegetable Oil for Gentle Removal
For a natural, non-toxic option, especially if you have pets or kids frequently using the deck, olive oil or vegetable oil can loosen pitch without harsh chemicals. Pour a small amount of oil directly onto the sap and let it sit for 10–15 minutes. Then rub gently with a cloth or soft brush to lift the sap. Rinse the area afterward with warm, soapy water to remove any oily residue. This method works best on fresh sap and softer woods like pine and cedar.
7. Try WD-40 for Stubborn Build-Up
WD-40, a popular household lubricant and cleaner, has surprising efficacy in breaking down sap. Spray a small amount directly on the pitch and allow it to penetrate for several minutes. Then wipe with a clean rag or scrub gently with a nylon brush. WD-40 is safe for use on many wood surfaces but should be used sparingly and followed by soap and water to remove the oily residue. As with all chemicals, test on a small, hidden section first.
8. Use Baking Soda and Vinegar for Eco-Friendly Cleaning
A paste made from baking soda and white vinegar offers a more environmentally friendly alternative for sap removal. Mix equal parts into a paste and apply to the pitch with a cloth. Let it sit for a few minutes before gently scrubbing with a soft brush or sponge. This method is most effective on newer sap deposits and is best suited to unsealed wood or decks where you’re avoiding commercial products. It’s gentle on the wood and safe for surrounding plants and soil.
9. Sand the Affected Area for Stain Removal
If the sap has dried and left a stubborn dark stain, or if it has soaked into the grain, light sanding may be the most effective solution. Use fine-grit sandpaper (150–180 grit) and work with the grain to remove the top layer of discolored wood. This method is best reserved for spot-treating individual boards or preparing the surface for refinishing. After sanding, always clean up dust thoroughly and reseal the area to protect against moisture.
10. Prevent Future Pitch with Regular Sealing
Once you’ve removed the pitch, consider applying a water-repellent wood sealer or stain to prevent future absorption of sap and debris. Sealing your deck not only improves its resistance to pitch but also protects against UV rays, mold, and moisture. Be sure to clean the deck thoroughly and allow it to dry completely before applying the sealant. Reapply annually or as recommended by the product manufacturer to maintain the deck’s defense against organic contaminants.
Things to Consider When Sealing Your Deck
Before sealing your deck, it’s important to choose the right type of sealant or stain for your specific needs. Transparent sealants enhance the natural beauty of the wood, while semi-transparent or solid stains offer additional color and UV protection. Consider the weather conditions during application, as most sealants require a dry day with moderate temperatures to set properly. Always follow the manufacturer’s instructions regarding drying time and the number of coats needed. Additionally, check for any signs of damage, such as cracks or loose boards, and repair them prior to sealing to ensure a smooth and effective application.
Common Mistakes to Avoid
When sealing wood, it’s essential to be aware of common mistakes that can compromise the effectiveness and longevity of the finish. One frequent error is failing to properly clean the wood surface before applying the sealant. Dirt, grease, or old finish residues can prevent the sealant from adhering properly, leading to uneven coverage or peeling. Another mistake is applying the sealant in extreme weather conditions, such as high humidity, intense heat, or freezing temperatures. These conditions can interfere with the drying process and result in a subpar finish.
Over-application of sealant is another pitfall; using too much product can lead to excessive buildup, which may crack or peel over time. Lastly, skipping routine maintenance after sealing can reduce the durability of the protection and leave the wood vulnerable to damage over time. By avoiding these mistakes, you can ensure a smooth and long-lasting application.
Conclusion
Removing pitch from wooden deck boards doesn’t have to be a struggle. Whether you prefer commercial cleaners or household remedies, there’s a method for every scenario—from fresh drips to deep-set stains. These ten approaches provide a versatile toolkit to address sap at any stage, ensuring your deck remains clean, safe, and beautiful throughout the seasons. Thanks for reading, and we hope this has given you some inspiration on how to clean pitch off wooden deck boards!
