Deck Oils

May 28, 2024

Are There Any Positive Benefits To Using Decking Oils on Your Black Locust Lumber Decking? Read On For the Pro’s and Con’s!

Are decking oils necessary??


There has been a lot of confusion in the building industry and also by environmentally conscious consumers, as to whether the use of decking oils is really necessary. 

In this article I hope to enlighten and educate all those who want to avoid the use of harmful chemicals called VOC’s (Volatile Organic Compounds). I want to discuss how the natural weathering process occurs so that staining and decking oils are not needed. I will also go into detail about the impact of decking oils when it comes to slip resistance and toxicity.

UV Exposure

Every material known to man is subject to UV exposure. Things like copper roofs will go to a green patina when exposed to the sun and the environmental elements. The same goes for every wood exposed to the outdoor elements. It will turn grey with time. Here are some examples of boardwalks and decks that have naturally greyed without the use of decking oils and chemicals.

There are many products that will delay the UV decay and extend the time of the natural weathering process. However, these products, such as decking oils,  will never stop this natural occurring process completely. Decking oils and other products have to continually be reapplied approximately every 2-3 years depending on the orientation of the sun exposure. This could cause you to have to reapply the decking oils yearly. 

Black Locust Lumber Decking left untreated with no decking oils will weather to an even silvery grey color. Each season you can be sure that your unoiled,  Black Locust deck will be free from any need of a cleaning, sanding, or decking oils.. Your chemical free, 100% natural Black Locust decking , wil reduce your outdoor chores and allow you to have more time to enjoy your deck and the great outdoors.


Decking oils will give your decking an enhanced appearance. However, they give very little effect to preserving the deck or increasing the longevity of your decking. 

There will be no long term reduction in surface checking and smoothness of your Black Locust Lumber decking. Leading Universities have actually done research studies on the effects of decking oils. The research indicated that Black Locust wood will actually develop a smoother finish over time without decking oils..

Yes, things do improve with age, just as wine also improves with time, naturally. 


The short answer to this question is 2 coats, and your deck may require many more.

Due to the Black Locust wood composition, multiple coats of deck oil will be required. Portions of the boards will absorb the decking oil readily while other sections will absorb at a reduced rate.

Once you have oiled your Black Locust Lumber Deck you have now begun the continuous cycle of maintenance.

You will have to continue to not only clean it but re-oil the Black Locust possibly every season.

The use of decking oils on your Black Locust Lumber deck will cause an uneven surface pattern. It will appear patchy or mottled due to the different amount of absorption rates.

A 2nd coat of decking oil, or multiple coats will be required to give you the consistent surface appearance.

With the natural composition of the Black Locust lumber, the decking oil will be absorbed at different rates, therefore, many coats of decking oil will be required to obtain 

the even color.

After the application of decking oils is complete, the Black Locust deck will be exposed to the UV decay and extended sun exposure.  It will begin to become mottled and patchy in appearance. This occurs because of the absorption rate in the actual board. This is a normal process and there is not much you can do about it.

By allowing your Black Locust Lumber Decking to go naturally to a silvery grey from the exposure to the sun. It will go slowly, evenly and natural with no chemical additives. When thinking about using a decking oil it's important to think about your labor, the increased material cost and the appearance before making this choice. You are ultimately creating a high maintenance situation for yourself.  When you add decking oil maintenance to your Black Locust decking, it takes away from your time to just enjoy it.

So, to answer your question, “Do I Need To Use Decking Oil on my Black Locust Lumber Decking?

The answer to that question is, once you have made that decision to use decking oils,  you now have begun the vicious cycle of high maintenance.


The only way to break the cycle of oiling and maintenance is sanding and striping the previous Black Locust decking surface.

The decking must be to its previous pre-oiled natural state and allow it to weather naturally.

This process is extremely labor intensive and just plain hard work!

Black Locust decking should be left natural and untreated.

Remember, just using one coat of decking oil will restart the never ending process of maintenance.

The net result, more work and less time to enjoy your Black Locust Lumber Deck.


One of the best and many benefits of purchasing a Black Locust Lumber Deck is its natural slip resistance.

This excellent quality is a direct result of its composition and the fact that it does not contain any natural oils.

Ipe, for example, which is a tropical hardwood,  uses its natural oils ensuring its longevity. 

These oils cause a very waxy textured surface and can make a Ipe deck surface very slippery in and around wet and damp conditions.

This slippery condition has been addressed by the design-build industry.

With this slip hazard, the industry has created an anti-slip, Ipe Decking profile.

In finding a solution to this hazard, this profile has multiple grooves to reduce the amount of standing water on the surface of an Ipe board.

It is especially useful in and around pool areas, docks and walkways.

By adding deck oils to Black Locust Lumber decking, you have now reduced the natural slip resistance.

This action will increase the likelihood of a slip and fall accident whether it is in a public space or in your own backyard around your pool!


When contemplating and sourcing a Black Locust Lumber deck  for your next project, some manufacturer’s may discuss or suggest the use of decking oils.

A material safety data sheet contains details you should be made aware of.

This important published information by the manufacturer of the decking oil is required by the US Government on the health and safety of all products.

Deck  Oils contain the following published on the material safety data sheet as follows:



-TOXIC SIGN                            


Why add these published toxic chemicals to a 100% natural product that does not require decking oils? Being naturally rot resistant, why would you want to add something that has zero benefit to the preservation of your Black Locust Lumber deck?

Imagine having your friends, family or more importantly children, walking or playing on a harmful chemically treated wood oiled deck, dock or walkway!

These toxic oils are also dangerous to marine life and are publicly listed as such by government regulations.


VOC’s are chemical elements that are both manmade and natural. 

Keeping in mind, an example of naturally produced VOC’s are pine and citrus oils.

These products have been known to cause headaches, dizziness, nausea and respiratory irritation.

Harmful side effects can occur because VOC’S cause both health and air quality issues. 

This is a reason for concern for both public safety and the environment.

Depending upon where you live, the amounts of VOC’s per gallon of decking oil are limited or even barred in certain locations.

Southern California, for example, has banned the usage of products that do not meet their limits for VOC contents.

Excessive amounts of VOC’s play a significant role in the formation of harmful gases in the atmosphere also known as smog.

Here is the million dollar question!

Would you use a decking oil on your Black Locust Lumber Decking

 that is toxic, kills marine life, and has spontaneous combustion qualities?

Not to mention the noxious oil odors and its restrictions which are clearly dangers of its use to the overall environment.

When combining all these negative check marks to the environment, Coupled with high maintenance and additional unnecessary costs for overall appearance of your Black Locust deck

the moral of this story, Just Leave Your Untreated, non-toxic Black Locust Decking natural!

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