Decking materials compared

How to choose between them

Every decking material is a trade between what you pay now and what you pay later, and the only variable that settles it is how long you intend to own the deck. Pressure-treated pine is the cheapest thing you can build and the most expensive thing to keep: cleaning and a fresh finish every two to three years, and boards to replace from around year ten. Composite is roughly double the installed price and then asks for an annual wash and nothing else. Somewhere between eight and twelve years of ownership, those two lines cross. Put your own numbers through the composite versus wood calculator to see where yours does.

The second variable is what the deck has to look like. Cedar and redwood have a grain and a colour that no composite matches convincingly when new, and they are the right answer on a period house or anywhere the deck is a visible part of the architecture. The catch is that they only look that way while the finish holds; a neglected cedar deck greys and erodes faster than pressure-treated pine does.

What the price per square foot includes

The figures on the cards above are installed costs — framing, fasteners and labour as well as the boards themselves. That matters when comparing against a supplier's board price, which is typically a third to a half of the installed figure. It also explains why upgrading material costs less overall than the sticker difference suggests: the framing, the footings and most of the labour are identical whatever goes on top.

Two material choices do change the framing. Nearly every composite and PVC brand requires joists at 16 inches on centre, and 12 inches for diagonal layouts, where 2x wood decking is permitted at 24. And tropical hardwood is dense enough that every fastening has to be pre-drilled, which adds real hours. The joist spacing calculator works out what your chosen material requires.

Maintenance, honestly

Wood needs cleaning once a year and refinishing on a cycle set by the product rather than the calendar — clear repellents annually, semi-transparent stain every two to three years, solid stain every three to five. Composite needs the annual clean and no finish. It does not need nothing: composite grows the same surface mould as wood in shade, and the board gaps still pack with debris that holds water against the frame below.

The frame is the part nobody budgets for. Whatever the surface, the joists, beam, posts and ledger are pressure-treated lumber, and they fail in a predictable order — ledger first where water gets behind unflashed boards, then post bases in ground contact, then joist tops under packed board gaps. The maintenance schedule covers the twenty-minute annual check that catches all three.

Where each material makes most sense

• Pressure-treated pine — tight budget, a deck you expect to rebuild or resurface within a decade, or a large footprint where doubling the material cost is not realistic.
• Cedar or redwood — when appearance matters more than upkeep and you will actually do the refinishing. Redwood is materially cheaper on the West Coast than anywhere else, which is worth checking locally before ruling it out.
• Composite — long ownership, limited appetite for maintenance, or a deck somewhere awkward to work on. Choose a lighter colour if it faces full sun.
• PVC — constant moisture, poolside, or anywhere organic material in the board is a liability. It is the lightest and the most dimensionally active with temperature, so it wants the widest board gap.
• Tropical hardwood — where the deck is a feature and the budget allows. Check the supply chain; certification varies a great deal by species and importer.

Questions people ask