Linseed Oil and Turpentine Ratio for Decking: What Do You Need to Know?

A Deck can be a functional addition to any outdoor space. It can be a great area to entertain guests or chill with the family. The decking of a building is an elevated platform beside or attached to the exterior of a house, and constructors typically make it from wood. As with everything, we must maintain our deck to guarantee its longevity. Protective substances are one way to maintain or preserve a deck’s integrity. We want to look at one such protective substance, linseed oil, and what we need to know about mixing it with turpentine.

One of the most important things to know is the correct ratio of turpentine and linseed oil we need. As such, this article will explore what you need to know about linseed oil and turpentine. Also, we look at how to choose the correct ratio or percentage of linseed oil and turpentine for decking. Then we will look at the advantages and weaknesses of linseed oil for deck finishing and consider some alternatives.

What is Linseed Oil and Why Mix It with Turpentine?

Linseed or flaxseed oil is an industrial plant-based oil produced from flax seeds. Regarding housing and home repair, linseed oil is a common component of many wood finishes to protect and preserve the wood. Because linseed oil can penetrate deep into the wood, it effectively protects it from water and other types of damage. Linseed oil forms a moisture-resistant coating that, unlike paint, does not fracture with age. Also, Linseed oil prevents moisture from seeping beneath the surface and causing wood rot.

Additionally, since linseed oil is a natural oil, it is an environmentally friendly choice for wood protection. Linseed oil is non-toxic and biodegradable.

There are three varieties of linseed oil: raw linseed oil, polymerized linseed oil, and boiled linseed oil. First, raw linseed oil is pure with no chemicals or additives. Second, polymerized linseed oil is the product of Heating linseed oil to around 300°C. Third, boiled linseed oil is linseed oil that has undergone treatment with additives and drying agents, making it easier to use. Raw linseed has a longer drying time. Polymerized linseed oil improves on that, while boiled linseed oil dries fastest and seeps deeper into the wood. Boiled linseed oil is the most popular variant of linseed oil used in finishing wood.

Despite its strength in preserving wood and slowing its deterioration, linseed is a slow-drying oil. The slow-drying nature of linseed oil is why we mix it with turpentine.

Turpentine is a solvent made from the resin of some pine trees. The purpose of turpentine in wood finishes includes substance thinning and as a cleaning agent. There are different types of turpentine: wood, gum, and kraft. Gum turpentine is the most popular and suitable for natural wood finishes. Turpentine has a powerful smell, although there is an odorless variant. Turpentine is also flammable, so be careful when working with it.

The ability of turpentine to dissolve substances is why we mix it with linseed oil. When combined with linseed oil, the turpentine will thin it out, reduce its viscosity and make it easier to apply and work with. As a result, turpentine helps counteract linseed oil’s slow-drying nature. Turpentine will improve the drying time of linseed oil, helping to create a smoother and more consistent wood finish for decking.

Importance of Selecting the Appropriate Linseed Oil and Turpentine Ratio for Decking

Choosing the correct ratio of linseed oil and turpentine for decking is vital for the following reasons:

  • Enhancing The Durability of The Deck: the main reason for applying a wood finish to the deck is to preserve it and ensure its long-term durability. To achieve durability of the decking, we must not use too much or too little turpentine in mixing it with linseed oil.
  • Maintaining The Natural Color of The Wood: different wood types have a natural look, and applying a wood finish may change the color. We want to limit how much the Linseed oil changes the natural look of the decking’s wood as much as possible. So, selecting the correct ratio of linseed oil and turpentine is vital to keep the wood’s color close to its natural one.

How to Choose and Mix the Right Ratio of Linseed Oil and Turpentine for Decking

The correct ratio of linseed oil and turpentine for decking will depend on factors, including the climate, the type of wood used for decking, and the state of the deck. Some recommend a 1:1 linseed oil and turpentine ratio in areas with low humidity (under 40%). Generally, and per our recommendation, you should use 1:2 linseed oil and turpentine to finish your deck. This ratio will help prevent the turpentine from being too sticky.

After selecting the ratio, you need to mix it. Here are the basic steps:

  1. Mix the linseed oil and turpentine in a container using the selected ratio. It is best to combine them in glass containers with tight screws.
  2. Cover the mixture tightly.
  3. Leave the mix for a few days so the substances can mix well.

How To Apply Linseed Oil and Turpentine Mix to The Deck

  1. Clean the surface of the deck. It is essential to clean the surface to guarantee an excellent finish. So, sweep the surface with a broom. For new decks, inspect them for stains before applying the mixture. If there are stains, use warm soapy water to scrub the surface. Wait for the surface to dry. Supposing you have previously finished the deck, clean it with a power washer to remove dirt and mold stains.
  2. Pour the mixture into a paint tray or container.
  3. Put a lint-free towel into the mixture. Wear rubber gloves and soak the towel in the mixture until it absorbs. Make sure the towel is not dripping. Squeeze and twist the towel if needed.
  4. Wipe the deck’s surface with the lint-free towel. As you do so, ensure you follow the direction of the grain. Grain direction refers to the alignment of the wood fibers on the deck. The fibers may run vertically, horizontally, or diagonally across the surface.
  5. Spread the mixture evenly to create a uniform coat of oil on the deck’s surface. The spread should leave a wet surface behind and not puddles.
  6. Polish the finish with a dry towel 30 minutes after applying the mixture. Doing this will smoothen the finish and remove puddles of oil.
  7. Leave the deck for a day for the linseed oil to soak in and dry.
  8. Apply another coat of the linseed and turpentine mix. The second coat can be lighter. This second coat ensures that the mixture penetrates the wood better and protects it.
  9. Clean the deck with a dry towel. Ensure you leave no puddles.
  10. Leave the deck to dry.
  11. Clean the deck and apply the mixture every year to maintain the effectiveness of the finishing and keep up the deck’s durability.

Advantages Of Linseed Oil for Decking

Some of the advantages of linseed oil include the following:

  • It makes it easy to sand out scratches and dents from the surface of a deck protected with linseed oil.
  • Raw and polymerized linseed oil are non-toxic, eco-friendly, and contain non-volatile organic compounds.
  • When correctly applied, linseed oil maintains the natural depth of color and texture of the deck’s surface.
  • You can combine linseed oil with other wood finishes to preserve your deck.
  • Linseed oil and turpentine mixture are less expensive than their alternatives.

Disadvantages Of Linseed Oil for Decking

Some disadvantages of using linseed oil include the following:

  • You need to reapply linseed oil intermittently to protect the deck effectively in the long term. Doing this again and again, can be bothersome.
  • Decks protected with linseed oil might be more susceptible to scratches than wood finishing alternatives like acrylic resin or varnish.
  • Temperature changes may lead your deck to bleed oil.
  • At times, linseed oil-finished wood may become yellow with age.

Alternatives to Linseed Oil and Turpentine Mixture

While linseed oil is a popular and relatively cheap way to finish the decking, there are some alternatives, including:

  • Tung Oil: produced from tung tree seeds, pure tung oil, unlike raw linseed oil, dries fast and lacks the yellowing effect of linseed oil. Like linseed oil, tung oil is eco-friendly. However, tung oil may need up to 5 or more coats to adequately protect the wood.
  • Varnish: varnish is a popular wood finish that you can use for decking. It will give the deck a glossy appearance while maintaining its natural color. However, varnish can be more challenging to apply and requires more skill. Many varnishes are derived from natural substances dissolved in a solvent.
  • Teak Oil: teak oil is also a natural oil. It is extracted from linseed oil and is known for its ability to protect wood surfaces. The difference between teak and linseed oil is that the linseed oil in teak has been tweaked to dry faster and work well on teak wood. Teak oil provides a natural matt finish. Also, teak oil is easy to apply and dries fast. It is a popular choice for outdoor furniture and home decks. Teak oil works best on hard and exotic wood, especially teak wood. So, if constructors used teak wood in making the deck, this may be the oil you need for your finish.
  • Polyurethane: this is a synthetic coating that is renowned for its water resistance. It is more commonly used on floors but also on decks. However, unlike natural oils, polyurethane does not penetrate deep into the wood fibers.
  • Acrylic Resin: this is also a synthetic coating. Acrylic resin is used on outdoor furniture, including decks. It is easy to apply and dries quickly. Additionally, acrylic resin comes in a variety of colors. While oil-based oils fade with age as they penetrate the wood, acrylic resin chips and breaks away because it lays on top of the wood.

The many alternatives to linseed oil have their advantages and disadvantages. It is up to you to research the relative benefits of each and figure out if one of them might be a better option for decking than linseed oil. Depending on the condition and type of wood, weather conditions, and more, an alternative may be more suitable for decking than linseed oil.


This article discussed using linseed oil and turpentine as protective substances to preserve a deck. We detailed the correct ratio of both substances you should use. Linseed oil, while great at protecting wood and your deck’s surface from water, ultraviolet rays, and other damages, is slow to dry. Hence, we must mix Linseed oil with turpentine to thin it out, make it easier to apply, and improve drying time.

Using the correct ratio of linseed oil and turpentine is essential for maintaining the durability and natural color of the deck. We recommended a 2:1 linseed oil and turpentine ratio. However, you should consider the wood used for the deck, its condition, and the climate in deciding the ratio. We have also looked at the advantages and weaknesses of linseed oil and highlighted some alternatives for your consideration.