Deck material guide
There are three decking families and the choice between them is mostly about one trade-off: money now versus work later. Here is what each one actually costs you, including the parts the sales sheet leaves out.
Pressure-treated pine
Southern yellow pine, treated to ground-contact or above-ground specification. The default choice in North America for good reason: it is the cheapest, it is available everywhere in every length, and it is structurally capable of spanning at 16″ on centre without argument.
- Cost: roughly $4–$6 per sq ft in material
- Lifespan: 10–15 years before boards start to cup and check visibly; longer if maintained
- Maintenance: seal or stain every 1–2 years
- Watch for: it arrives wet and shrinks. Boards fitted tight will open up gaps on their own — which is why the gap specification assumes dry service.
The underrated advantage: you can buy one extra board in the same run five years later and it will weather to match. Try that with composite.
Composite
Wood flour and polymer, extruded into boards. Capped composites have a protective shell that resists staining and fading; uncapped ones absorb moisture and grow mould in wet climates.
- Cost: roughly $9–$14 per sq ft in material
- Lifespan: 25–30 years for capped lines, with warranty terms that vary enormously
- Maintenance: wash it. No sealing, no sanding
- Watch for: it is heavier and more flexible than wood, so it usually requires 16″ or closer joist spacing — and some products require 12″. The framing cost goes up with the decking cost, and that is not in the per-square-foot price.
The maintenance saving is real but often overstated. Composite eliminates staining, not cleaning, and a dark composite deck in full sun gets uncomfortably hot — measurably hotter than wood.
Hardwood: ipe, cumaru, mahogany
Dense tropical hardwoods, sold by the board foot rather than the linear foot. Ipe is roughly three times the density of pine and needs different everything: carbide tooling, stainless fasteners, pre-drilled holes, and a gap of about 1/8″ because it moves less.
- Cost: roughly $22–$38 per sq ft in material
- Lifespan: 30–40 years, and it can be sanded back to new
- Maintenance: oil annually if you want the colour; leave it to weather to silver if you do not
- Watch for: fastener corrosion. Standard screws will stain the wood black within a season — stainless or hot-dipped galvanised only.
Use the board foot calculator rather than a linear-foot estimate, because hardwood is priced on volume and random widths make linear footage meaningless.
The comparison that matters
| Material | Material $/sq ft | Joist spacing | Refinish interval |
|---|---|---|---|
| Pressure-treated pine | $4–6 | 16″ | 1–2 years |
| Composite (capped) | $9–14 | 12–16″ | None |
| Hardwood | $22–38 | 16″ | Annual oil (optional) |
On a 192 sq ft deck the decking line runs about $1,000 for treated pine, $2,000 for composite and $4,800 for hardwood. Railing, at $55–$110 per linear foot, often costs more than any of them.
What this page does not do
- It does not quote current prices. Lumber moves with the futures market; composite is comparatively stable. These are planning ranges, not quotes.
- It does not rank brands. We do not take payment for placement, and we have not tested these products side by side.
- It does not cover every material. Aluminium, PVC and modified wood (thermally treated, acetylated) all exist and all sit in different places on this trade-off.
Questions people actually ask
What is the cheapest deck material?
Pressure-treated pine, at roughly $4–6 per square foot in material. It is also the most available and the easiest to match later, at the cost of sealing every year or two.
Does composite decking need closer joist spacing?
Often yes. Many composite products require 16″ on centre and some require 12″, because the boards are more flexible than wood. That increases framing cost, which per-square-foot comparisons usually ignore.
Is hardwood decking worth it?
At $22–38 per sq ft, it is a 30–40 year material that can be sanded back to new. It makes sense where the deck is a permanent architectural feature, not where it is a budget-driven build.
How much gap between hardwood deck boards?
About 1/8″, less than the 1/4″ used for pressure-treated pine, because dense tropical hardwoods move much less with moisture.
Can I mix materials?
Yes, and it is common: pressure-treated framing with composite or hardwood surface. Keep fasteners compatible — stainless or hot-dipped galvanised where they touch treated lumber or hardwood.