How to Finish & Treat Cedar for Outdoor Use

Cedar is a classic choice for outdoor woodworking projects because of its natural resistance to decay and insects.

But to get the most beauty and durability from cedar wood, it’s important to properly prep, apply the ideal wood finish, and maintain it. This article provides expert guidance on treating cedar for exterior applications like patio furniture, planter boxes, and decking.


Cedar is excellent for outdoor use due to its natural resistance to decay and pests. While cedar inherently withstands outdoor elements, treating it enhances its beauty, durability, and lifespan.

The Appeal of Cedar for Outdoor Projects

Cedar is a favorite among woodworkers for outdoor projects, and here’s a quick refresher on why:

  • Weather-Proof: Cedar resists rain, snow, and sun.
  • Pest-Resistant: Naturally wards off termites.
  • Visual Allure: Rich hue and fine grain.
  • Easy Work: Simple to cut, shape, and finish.
  • Sturdy: Durable for outdoor longevity.
  • Lasts Long: With care, remains robust for years.
  • Unique Aroma: Deters certain pests.

How to Treat Cedar Wood for Outdoor Use

Pure Tung Oil

When it comes to treating cedar for outdoor use, understanding the available products, their application methods, and their advantages and disadvantages is crucial.

Oil-Based Finishes:

  • Pros:
    • Deep penetration ensures enhanced natural color.
    • Provides a protective layer against moisture.
    • Offers a warm, rich finish and preserves cedar’s inherent beauty.
  • Cons: Might require frequent reapplication; can attract dirt if over-applied.

Application: Apply with a brush in the direction of the grain. Allow it to penetrate and wipe off excess.

Product Recommendation: Boiled linseed oil and tung oil


  • Pros:
    • Acts as a barrier against moisture, UV rays, and potential stains.
    • Can be clear or tinted.
    • Durable; resistant to wear; available in various sheens.
  • Cons: Can be challenging to apply evenly; might yellow over time.

Application: Apply using a brush or sprayer. Ensure a well-ventilated area.

Product Recommendation: Polyurethane


  • Pros:
    • Enhances or alters cedar’s color.
    • Provides protection against UV rays.
    • Highlights cedar’s grain; offers UV protection; available in various colors.
  • Cons: Might require reapplication more frequently; can be harder to match if re-staining.

Application: Use a brush or roller. Apply in the direction of the grain. Multiple coats might be needed for the desired opacity.

Product Recommendation: Semi-transparent stain

Treatment Types Comparison (Oil-Based Finishes, Sealants, Stains)

Treatment TypeProsConsApplication MethodProduct Recommendation
Oil-Based FinishesDeep penetration, protective layer, warm finishMight require reapplication, can attract dirtBrush in grain direction, wipe off excessBoiled linseed oil, tung oil
SealantsBarrier against moisture, UV rays, various sheensChallenging to apply, might yellowBrush or sprayer, well-ventilated areaPolyurethane
StainsEnhances color, UV protection, highlights grainFrequent reapplication, hard to match re-stainingBrush or roller in grain direction, multiple coatsSemi-transparent stains

Application Tips:

  • Preparation: Start with a clean, sanded surface for even application and better finish adherence.
  • Technique: Brushes are ideal for detailed areas, while rollers or sprayers suit larger surfaces. Follow the wood grain.
  • Maintenance: Check the finish periodically. If signs of wear appear, reapply the finish to maintain the cedar’s appearance and protection.

Here’s a beautiful set of cedar planter boxes that are getting the boiled linseed treatment.

Maintenance Tips for Treated and Untreated Cedar

Whether you’ve opted to treat your cedar or leave it in its natural state, regular maintenance is key to ensuring its longevity and preserving its beauty.

Here’s a guide to caring for both treated and untreated cedar:

Regular Cleaning:

  • Importance: Dirt, mildew, and algae can accumulate on cedar over time. Regular cleaning prevents these from causing damage or discoloration.
  • Method: Gently scrub the surface with a soft brush and mild soapy water. Rinse thoroughly with clean water.

Inspect for Damage:

  • Importance: Early detection of issues like cracks, splits, or insect damage can prevent more significant problems.
  • Method: Periodically inspect the cedar for any signs of wear or damage. Address issues promptly to prevent them from worsening.

Reapplication of Treatments:

  • For Treated Cedar: Treatments can wear off over time, especially in high-exposure areas.
  • Method: Check the manufacturer’s guidelines on the frequency of reapplication. Ensure the surface is clean before re-treating.

Moisture Management:

  • Importance: Excessive moisture can lead to rot or warping.
  • Method: Ensure proper drainage around cedar structures. To prevent direct ground contact, ensure that items like decks or benches are slightly elevated with concrete blocks or a similar product.

Addressing Common Issues:

  • Warping: Caused by uneven moisture absorption. Ensure even finishing and regular cleaning.
  • Fading: Natural aging or UV exposure can cause fading. UV protectants or periodic re-staining can help.
  • Insect Damage: While cedar naturally repels many pests, it’s not immune. Regular inspections and prompt treatment can mitigate damage.

Frequently Asked Questions

Here, we address some of the most common queries related to cedar treatment and its use outdoors:

Does untreated cedar rot?

  • While cedar is naturally resistant to decay, it’s not immune. Over time, untreated cedar can show signs of rot, especially in damp conditions. Regular maintenance and ensuring proper drainage can help mitigate this.

How often should I re-treat my cedar outdoor furniture?

  • The frequency depends on the type of treatment and environmental exposure. Generally, re-treating every 2-3 years is recommended, but always refer to the manufacturer’s guidelines.

Can I paint over treated cedar?

  • Yes, but ensuring the cedar is clean and dry is essential. Using a primer before painting can also help achieve a smooth, lasting finish.

Why is my cedar turning gray?

  • Cedar naturally grays over time due to UV exposure. This can be prevented or reversed using UV-blocking finishes or stains.

Can cedar be in direct contact with the ground?

  • While cedar is more durable than many woods, direct ground contact can expose it to more moisture and potential decay. Using barriers or elevating cedar structures can help prolong their lifespan.

How do I clean mold or mildew off my cedar?

  • A mixture of mild detergent and water and gentle scrubbing can remove mold or mildew. Ensure you rinse the cedar thoroughly afterward.

Does sealing cedar affect its natural aroma?

  • Some sealants might initially reduce the intensity of cedar’s aroma, but the scent typically returns as the sealant cures.

Is cedar safe for garden beds or planters?

  • Yes, cedar is a popular choice for garden beds due to its natural resistance to decay and pests. If you’re concerned about chemicals from treatments, opt for natural or organic sealants.

How does cedar fare in coastal or high-humidity areas?

  • Cedar holds up well in various conditions, but regular maintenance and periodic treatments can help combat the added moisture and salt exposure in high-humidity or coastal areas.

Choosing the right treatment (finish) and applying it correctly enhances cedar’s robust and versatile nature. Understanding cedar’s specific needs will help your projects remain beautiful and durable for years to come.

2 thoughts on “How to Finish & Treat Cedar for Outdoor Use”

  1. Appreciate the article Matt. I have a couple questions. I’m considering using aromatic cedar for garden beds about 18″ high. I’m reading conflicting information on the value of that. The wood I’m looking at is from Missouri (I’m in Indiana) and is 1 1/2″-2″ thick. I’m thinking of 4×8′ garden beds and just wondering what you would think of the longevity of that type of cedar. Thanks
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