March 2, 2023

Cedar vs Pressure-treated deck

Cedar and pressure-treated wood are both popular options for deck building, but they have some notable differences. If you want to build any wood item, look at its durability, cost, size, texture, resistance to insects, and weather conditions. As you look at these features, match them with your needs. This article will explain their unique features, strengths, and weaknesses. 

Characteristics of cedar wood


It is one of the most durable woods that lasts for decades. It has a natural resistance to deterioration, making it ideal for interior and exterior home use. Cedar fibres contain compounds called thujaplicins

These are preservatives that make the wood long-lasting. The finish will make it last for decades, even in harsh environments. These compounds also give the wood a unique aroma. Cedar heartwood is popular for its high decay resistance. It has a durability Class 2 in Europe and Australia, the highest category for the durability of softwood.

Weight and ease of use

Its open cell structure makes it less dense than other softwoods. It is lightweight, making it easy to move from place to place. Its low density and consistency make it an ideal wood to cut, saw, nail and glue. You can even use a handsaw easily through the wood.

Texture and grain 

It has a uniform texture, straight grain, and no resin. The even grain and consistent density make cedar wood less likely to swell, warp, cup, and twist than other soft and hardwoods. It retains a unique appearance for quality furniture.

Its beauty comes in many hues. Cedar is free of the pitch and resin found in other softwoods, making it ideal for a wide range of finishes. Cedar ranks at the top in its ability to accept and maintain a finish.

Cedar’s low-density increases insulation by transporting less heat through interior wall paneling or exterior wall siding than brick, stone, vinyl, or gypsum drywall. It helps keep interiors warmer in cold weather.


Blocks noise

The interior paneling makes it a barrier to quality than most products marketed for those applications.


Cedar wood has excellent dimensional stability due to its low wood density and low shrinkage factor. Its moisture content at the fibre saturation point is 18 to 23%, compared to 25 to 30% in most softwoods. 

Cedar shrinks and swells minimally, with minimal changes in humidity. Lower absorption of water gives you a high extractive content blocking wood absorption. Cedar is for paneling, moldings, and other applications where dimensional stability and water repellency are.

Thermal and insulating properties

Cedar has good insulation value because of its low wood density and coarse texture. It is the best insulator among the softwood species.

Homes built with Cedar wood will be cooler in the heat of summer and warmer in winter, unlike denser species. It can dampen vibrations, making it effective in paneling and molding where it is desirable to reduce noise.

Flame spreading rate

The flame-spread rating of Western Red Cedar is 67 to 73, and the smoke-developed classification is 98. These ratings regulate the use of materials where the potential to generate smoke or smoke control movement matters.

 Due to its low flame-spread rating, it performs better than most dense softwoods, which have flame-spread ratings of around 100. Cedar has a flame-spreading rate and a smoke-developed classification below the maximum limits set by most building codes.

Finish and Workability 

Cedar takes a variety of coatings, paints, and stains well, particularly when dried and primed. It planes and sands cleanly. Due to its low wood density, it requires little energy to saw. Cedar also glues well with a wide range of adhesives and gluing conditions.

Characteristics of pressure-treated wood

Resistance to rot. 

The chemical compounds used to treat wood make it resistant to fungi that cause wood to rot. It has protection from insects and treatments to repel insect threats like termites and ants.

Ease of use

Pressure-treated wood is light and fastened to other supports with ease. It can easily be cut to size using a saw, and fasteners like nails will penetrate it easily. It is lightweight and easy to maneuver. 

Pressure-treated lumber is a versatile and convenient building material for any project. Due to its resistance to water, fungal growth, and insect infestations, whatever is built with it will be durable and will last for years with minimal maintenance. 


Pressure-treated wood has undergone a process to make it more durable and less susceptible to decay, insect infestation, mold, and water damage. The process can even make the wood fire retardant. It is for residential indoor and outdoor use. The wood is treated with water-borne preservatives such as CCA-treated wood and used in decks, fences, docks, and building structures.

Pressure-treated lumber will last longer in any environment with consistent moisture. Its insect and fungal resistance also help it to outlast natural wood. Since it is denser than untreated wood products, it has increased strength. It is much lighter and compared to materials like steel, it is resistant to oxidation.

Moisture resistance

If you leave the pressure-treated deck in moist or wet environments, it will not soften. That is how it shuns away fungi, bacteria, and other microorganisms. Pressure-treated lumber uses a chemical compound based on copper, a natural biocide, protecting it from decay in moist environments. After treatment, the lumber is for decks constantly exposed to the elements.

Fungal resistance

Pressure-treated lumber uses copper-based compounds, such as alkaline copper quaternary or copper azole, to prevent fungal growth (Ptw-safety When used in combination with other compounds, it also provides insect resistance. The chemicals allow pressure-treated lumber in applications, where it will be consistently moist, such as basements.

Insect resistance

Insects like termites and carpenter ants do not threaten any structure built with pressure-treated wood. The copper compounds in pressure-treated lumber protect from insect damage, and additional chemicals, such as borate or, less frequently, arsenic compounds, can be added to stop insect activity.

Pressure-treated lumber protects the rest of the structure from insect damage and other insects, such as cockroaches and spiders.


Pressure-treated lumber is available in multiple sizes for different applications. For building purposes, it comes in standard dimensional lumber sizes. It is also planking for deck flooring or siding and in many other styles for more applications.

Durability and lifespan

A cedar deck lasts at least 20 years without any rot or decay problems, whereas treated lumber is more susceptible to weather damage. Pressure treated deck lasts a decade before the splitting and cracking start.

Cedar is durable as it expands and contracts, whilst pressure-treated wood is more prone to splitting and cracking.

Maintenance and upkeep

Cedar requires only annual cleaning, while a pressure-treated deck requires regular cleaning.


Pressure-treated wood cost is less affordable than untreated wood. Cedar’s price tag can be justified since it can last for decades. It ends up being more economical in the long run. A piece of cedar for 20 would cost around 14 for a similar size piece of treated lumber.

Environmental impact

Cedar is environmentally friendly if the lumber is sourced from a sustainably managed forest. In contrast, pressure-treated wood cannot be burnt and should be taken to a treated wood disposal site.


In conclusion, deciding between a cedar or pressure-treated deck requires an informed comparison. For affordability, consider pressure-treated wood, but if you want a long-lasting item, you may have to go for cedar. For safety, you may have to go for cedar which you can dispose of anywhere. The pressure-treated deck gives you multiple sizes to choose from. As you take your top pick, consider your preferences. 

David D. Hughes

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