When it comes to decks, homeowners usually start with this question: what should the deck be made of? The answer lies at the intersection of budget, aesthetics, maintenance requirements, and how the deck will be used. Site-specific factors such as ventilation, joist spacing and whether you need sheltered dry space under the deck can push the decision one way or another.
Below is a straightforward, contractor-caliber walkthrough of popular options and where each one makes sense.
Pressure-treated: the budget workhorse
Pressure-treated (PT) lumber remains the most economical path to a beautiful deck, and it’s far better than the green-tinted boards many of us remember. The predominant colour is a soft brown, and current preservatives (predominately copper) are safer as well as effective. PT is available for everything from framing (2x4s to, 2x12s; 4×4 and 6×6 posts) to decking (typically 1-¼” x6”) with bevelled edges.
Strengths
PT’s biggest strengths are cost and availability. It’s stocked almost everywhere and suits both framing and decking applications. PT can be stained or painted, and can last up to 20 years.
Weaknesses
There are several limitations to pressure-treated decking. The lumber often contains knots, which are less aesthetically pleasing, and it can split or splinter as it weathers. It typically arrives damp and shrinks slightly as it dries, leaving gaps. Without proper airflow underneath, it deteriorates more quickly and may twist or warp. If it’s stained or painted, the work needs to be redone on a regular basis.
Cedar: warmer look, modest price premium
Cedar is a wood full of natural preservatives. Bugs just don’t like to attack it the same way they eat pine, spruce and other conifer and deciduous softwoods. Most local supply comes from Western Red Cedar, which has a beautiful golden-to-red/brown hue.
Strengths
Cedar’s appeal lies in its appearance and character. It has a naturally rich tone, feels cool underfoot, and provides a timeless look. Cedar decking offers a warmer, more refined grain than pressure-treated decking, with fewer imperfections. It looks great, smells great, and will last about as long as PT. “Select” grade cedar decking typically has tight, sound knots that remain stable over time. Homeowners can leave it to silver naturally, or preserve its tone with a clear or semi-transparent finish.
Weaknesses
The trade-off is cost and maintenance. Cedar is usually double the price of PT. While it can last just as long or longer, it needs regular cleaning and UV protection if you want to keep its original colour. Over time, untreated cedar will weather to a silvery grey. Which is not a bad look!
Composite: consistent look, long-lasting
Composite decking, from brands such as Trex, TimberTech and many others, blends polymers and other materials for consistency and minimal upkeep. While each manufacturer markets unique colours or grain patterns, core performance is similar across brands.
Strengths
The main strength of composite is high durability and low maintenance. Surfaces remain consistent, without knots, cracks, or splinters. Clip-fastening systems leave the surface free of visible screws for a sleek appearance. Properly detailed and ventilated, composite can last decades with only routine cleaning.
Weaknesses
Composite is, however, roughly three to four times the cost of PT. It’s also much heavier. That extra weight can require upsizing structural components, so there’s a cost there as well. Composite expands and contracts noticeably with temperature swings, so decks installed tight in summer may show gaps in colder months. Most systems require joists spaced 16 inches on centre and order lead times can reach several weeks, especially for specific colours or finishes.
Ipe and other exotic woods: dense and durable
Ipê is an exceptionally hard, oily hardwood sourced from tropical forests. It’s often chosen for its natural resistance to decay and its deep, rich tone. Want a deck that screams ‘luxury’? Ipê is a top contender. It replaces mahogany as a long-lasting hardwood, but like mahogany it has been logged to the brink in many parts of the world.
Strengths
The strength of Ipê lies in its durability. It resists rot, insects and wear, and can last for decades when installed correctly. It also accepts clip systems for a clean surface and offers a luxurious, high-end look.
Weaknesses
The limitations of Ipe are cost, availability, environmental impact and labour. Ipe far exceeds the cost of composite, must usually be sourced through specialty suppliers, and requires pre-drilling or specialized fasteners. The boards are quite heavy and can dull tools quickly.
Thermally modified timber: enhanced stability
Thermally modified timber (TMT), often ash, is real wood that has been superheated to improve its dimensional stability and durability without chemical treatment.
Strengths
The strength of thermally modified timber lies in the balance between natural appearance and engineered stability. Because of its high-temperature treatment, TMT expands and contracts less than other woods, offers a smooth finish, and comes in around the same price range as higher-end composite decking. It’s also lighter than exotic hardwoods and comes in consistent, rich brown tones.
Weaknesses
The main limitation of TMT is aesthetic variety. Colour options are usually limited to a few shades of brown, although we find it quite aesthetically pleasing. Availability can also depend on specialty suppliers, though it’s improving steadily.
Bamboo-resin composites: dense and precise
Bamboo-resin boards are formed from compressing tough, super-linear bamboo fibres together with synthetic resin, creating an extremely dense, rigid product.
Strengths
Bamboo-resin decking is so strong and rigid that boards with tongue-and-groove edges can meet end to end without landing on a joist. This is a decking that is incredibly stable and resists movement, creating a refined hardwood-floor effect with shorter board lengths. It’s well suited to modern deck layouts where pattern and alignment matter.
Weaknesses
The main drawbacks are weight and selection. Boards are heavy, colour choices are limited, and most products come in shorter lengths—typically four to six feet. Pricing is comparable to composite and thermally modified timber, with supply through specialized dealers.
Waterproof decks: choose materials with moisture in mind
Some decks need dry space beneath for a patio or storage. This usually means a membrane above the framing with decking laid overtop, or an under-joist collection system. Both approaches trap some moisture and raise humidity.
In these situations, composite performs best, hands down. Plastic is very good at resisting moisture absorption and swelling. Natural wood products—including PT, cedar, Ipe, TMT, and bamboo-resin—can degrade faster in moist environments. The key is to protect framing with flashing and allowing for airflow.
What decking should you choose?
Every decking material comes with its own mix of financial, technical, aesthetic and environmental factors. Your best choice? It really depends on your budget and your preferences. If you’re looking to create a dry space under your deck, composite decking is an obvious choice. Get a grooved, clip-fastened system for a sleek, smooth look. If not, the choice is yours.
When it comes time to replace your deck, natural materials such as cedar, ipê and TMT are easier to handle and dispose of. PT is separated at waste stations due to the chemicals used in the pressure-treatment process. Composite and bamboo-resin usually go to landfill, unless a manufacturer take-back program exists locally.
Would you like to learn more? We would love to discuss your ambitions with you. Please get in touch at your convenience.
