What is the best wood for outdoor decking? Outdoor decking guide

April 23, 2024

Comparison of outdoor decking materials from pressure treated wood to tropicals and Black Locust wood in search of a sustainable alternative.

Planning a porch, outdoor deck area or boardwalk can set you up for many challenges. 

There are several aspects by which you can differentiate between types of wood for outdoor decking. Price, maintenance, durability, color, installation and sustainability can all impact what you decide to pick in the end. 

The world is changing and the need for sustainable, truly green products are increasing in the landscaping and building industry. The use of toxic oils and chemical preservers on outdoor materials is becoming less and less attractive to the conscious consumer. We know choosing the right type of wood material for your outdoor decking project is crucial. As lumbermen with roots in the forestry industry, we created an outdoor decking guide to support you in making an informed decision. 

Comparison of wood materials for outdoor decking

Pressure Treated Pine for outdoor decking

Probably the most widespread and readily available type of outdoor decking wood material is pressure treated pine. Pressure treated pine has easy workability, making it very easy for anyone with only little knowledge and experience to cut and install. Pressure treated pine is also commonly available at a reasonable cost. 

Pressure treated pine outdoor decking material

Though widely available and easy to use, pressure treated pine requires a lot of maintenance and has a hazardous effect on the environment. Toxic chemical preservatives are used to treat the wood. Pressure treated pine is easily degraded by UV radiation and requires regular maintenance with the help of oils, water sealers and sp

ecial chemical solutions. It’s a hazardous material, it cannot be burnt.

Manufactured composite outdoor decking

Manufactured composite outdoor decking can be made up of a variety of different materials. Most commonly it is a combination of plastic and sawdust. Though sometimes made of recycled materials, it is not considered “green” as it is unsuitable for recycling after being combined with plastic. Composite decking materials are available in several different colors and styles.

Composite decking outdoor decking material

However, we advise you to do some research before purchasing composite outdoor decking material. When exposed to direct sunlight the surface gets extremely hot and the color fades over time from UV radiation. Installation can be tricky due to composite decking materials’ expansion properties. Though resistant to moisture, they change size and expand under hot temperature and contract when the temperature turns cold. Take the climate into consideration when calculating spacing between boards. 

Thermally modified hardwood outdoor decking

Thermally modified hardwood is a relatively new technology that has been around in the past couple of decades. During the thermal modification the appearance of the hardwood outdoor decking material changes. The color of the wood will vary due to higher or lower temperatures used during the process.

Thermally modified hardwood outdoor decking material before and after thermal modification (Photo source: Bleck&Bleck Architects)


Ultra high temperatures are used to dry, reduce the strength and preserve longevity of the wood, but this also means the production has a substantial carbon footprint. Since it is a very new technology the jury is still out on its longevity and raises end of life questions on whether it can be disposed of once out of use.

Tropical outdoor decking materials

Tropical hardwoods have been around for decades in the outdoor decking industry. They are one of the most durable and long-lasting outdoor decking materials available. There are several tropical wood types available for outdoor decking projects, however, Ipe is one of the hardest woods available, its durability is unquestioned. Due to its superior performance tropical hardwood decking material’s price continues to increase every year.

Ipe is a tropical hardwood outdoor decking material 

Tropicals and Ipe outdoor decking materials however require maintenance to uphold its durability. Toxic oils and chemicals are used to clean it and keep its beauty, which raises sustainability issues. Illegal logging in tropical rainforests also remains a concern to this day. While the U.S. bans import of illegally logged wood from the tropical areas, China does not. Every year China sells more than $15 billion worth of hardwood products to the U.S., which unwittingly fuels illegal logging of rainforests.

Sustainable outdoor decking alternative: Black Locust 

By now our reader might think “Is there no wood material that is 100% natural and durable at the same time?”. It is important to do some research and turn to some more sustainable decking material options that are available in the market. Our answer to the conscious consumer’s question is a reassuring one: there is a sustainable outdoor decking alternative. It is called Black Locust.

Black Locust outdoor decking material is a wood type that has been around for centuries. Pioneers used Black Locust wood to build houses, stick them in the ground as fence posts and even build ships that won wars. The reason behind this is that they knew Black Locust wood would last for decades, an outstanding 50+ years natural longevity without the use of ANY toxic chemicals. 

The most sustainable outdoor decking wood material: Black Locust lumber

Black Locust is a truly organic hardwood material that is just as durable as the endangered tropicals only without the use of chemicals. Left natural, the color of Black Locust outdoor decking weathers and develops a silvery-gray patina which will not affect the durability of the wood. Though it is a difficult log to cut, Black Locust Lumber specialists with several decades of experience with this unique wood type are available to assist you in bringing the perfect wood material to your outdoor decking or boardwalk project.

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