PVC or composite: what actually separates them in Ontario

Bottom line: this is not a ranking. Capped composite and cellular PVC overlap in price, appearance and warranty length, and both are sold by the same brands. They separate on four things: what happens where water sits, how hot the surface gets, how far the boards move with temperature — and, following from that, what the installer has to leave at every joint.

The confusion is partly the industry's own doing. "Composite" is used as a catch-all for anything that is not wood, and the same manufacturer often sells both materials under one brand. TimberTech sells Advanced PVC and Composite. Fiberon sells PVC lines and composite lines. Trex is composite except for one ignition-resistant PVC line sold in select regions. Choosing a brand does not choose a material.

What is actually inside each board

Capped composite is a wood-and-plastic core with a protective polymer cap. Canada's evaluations describe the two biggest sellers in almost the same words: Trex's boards are made from "equal parts of reclaimed hardwood sawdust and reclaimed/recycled low-density polyethylene," and Fiberon's from "equal parts of reclaimed hardwood sawdust and recycled high density polyethylene" with an HDPE cap. TimberTech describes its own composite as polymers "along with organic material like wood flour."

Cellular PVC has no wood flour at all. TimberTech describes its Advanced PVC as "engineered from recycled material — with zero wood or organic fillers," and Fiberon states plainly that "PVC decking contains no organic content." The Canadian evaluation of the AZEK boards sold across Ontario describes them as "solid-core foamed polyvinyl chloride with proprietary fillers and PVC alloy capping."

Two things follow from that last sentence, and both are worth knowing before a salesperson simplifies them:

• PVC is not "pure plastic," and composite is not always wood. The PVC boards carry proprietary fillers, and the composite shelf in Ontario now includes rice-husk and bamboo-based boards alongside the wood-flour ones. If the filler matters to you, ask what it is rather than which word is on the label.
• Cap coverage is a product question, not a material one. TimberTech says its Advanced PVC has a four-sided cap while its Composite collections have "a three- or four-sided cap." Fiberon's Paramount page currently describes the board as having a "co-extruded cap on four sides" in its specification block and a "three-sided cap layer" in its feature copy. Check the current spec sheet for the exact board — an uncapped groove is where a board is most vulnerable.

One thing they have in common. Every Canadian evaluation for these products — PVC and composite alike — states that the board "is not to be considered as an equivalent to dimensional lumber." Neither material frames a deck. The structure underneath is still pressure-treated lumber sized to the Building Code, which is covered in our deck framing guide.

Live prices

What each costs today

Live Composite Deck Shop board prices, paired to show where the money actually separates: the cheapest board of each material, then composite and PVC from the same brand.

Cheapest of each TimberTech Fiberon

trex-basics

Current price at Composite Deck Shop

Board lengths

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clubhouse-pvc

Current price at Composite Deck Shop

Board lengths

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Composite Deck Shop prices as of Sep 29, 2026 · CAD, before tax and delivery

Board prices only, per board as sold. Framing, footings, stairs, railings and waste move a deck budget more than the material does.

The manufacturer's own banding says the same thing: TimberTech places its Advanced PVC at $$–$$$$ and its Composite at $–$$$, with maintenance at $ for both. The bands overlap across most of their length. The entry tier is composite, but a mid-tier PVC board and a premium composite board can land in the same place, so the material rarely settles the budget on its own. Our guide to building a composite deck on a budget follows the rest of the money through a whole project, and the Ontario deck cost calculator works through it in order.

Water, docks and the freeze-thaw trap

The most common shortcut in a showroom is that PVC is waterproof, so it is the material for anything near water. The first half is close to true. The second half is contradicted by the PVC manufacturer's own page.

Fiberon states that Paramount PVC is "tested for use around fresh water, salt water and chlorinated water environments, and suitable for use in installations that may be temporarily submerged in water, like dock and pool stairs." The very next instruction is the one that matters here: "PVC boards should be removed from water sources where a freeze/thaw cycle may occur."

In Ontario that caveat swallows most of the permission. A set of dock stairs standing in a lake from November to April is exactly the freeze-thaw case the instruction describes. If the boards cannot be lifted out, waterside work needs the current instructions for the specific product and an installer who has read them — not a material-level rule of thumb.

Where the wood flour does show up

Away from standing water, the difference is smaller than the marketing suggests, but it is real and it has two published forms.

• Mould has nothing to feed on in PVC. Fiberon puts it as "nothing to promote mold growth, a big concern in damp areas such as lakes, marinas, or beachfront properties." TimberTech's comparison claims its Advanced PVC "shows no mold or moisture damage," and — to its credit — names the method in a footnote: an internal test simulating 49 days of exposure by holding saturated sponges against the underside of the samples. That is a manufacturer's own bench test, not an independent field result, and it is worth reading it as such.
• Composite can bleed tannins in its first season. TimberTech's 2026 care guide is direct about it: "Like any other wood-based product, our wood-polymer composite products may experience a naturally occurring process called extractive bleeding/tannins," causing temporary discoloration that weathers away, typically over 8 to 10 weeks. It is not a defect, but a homeowner who was told composite is inert will read it as one.

PVC has no wood core to decay; capped composite is engineered for decay resistance. Both still need gaps kept clear so the deck drains, air moving underneath, and no rubber-backed mats or tarps left down for months.

Heat under bare feet

This is the claim PVC is most often sold on, and it comes with a number: TimberTech publishes that its Advanced PVC "stays up to 30°F cooler in direct sunlight compared to many composites." The footnote is part of the claim, and the manufacturer repeats it in both of its installation guides: "all decking products will get hot in the sun. Additionally, the darker the decking color, the hotter it will feel."

Read together, those two sentences are the practical answer. Colour and shade can substantially change the result. Compare actual samples in the sun where the deck will sit; a material label alone cannot tell you whether a surface will be comfortable barefoot.

The heat problem that actually damages decks is reflected sunlight, and it affects both materials. Both TimberTech guides warn that low-emissivity (Low-E) window glass can concentrate reflected sun badly enough to make decking "melt, sag, warp, discolor, increase expansion/contraction, and accelerate weathering." The fix in both guides is the same: extra framing, joist spacing tightened to 6–8 in. maximum in the affected area, and top-down fasteners rather than hidden clips. If your deck sits below a wall of newer windows, raise it before the boards are ordered.

Movement, gapping and the day you build

Temperature-driven movement is important for both materials. Composite also contains wood fibre, so moisture exposure still matters. How much they move, and what the installer must leave for it, is the sharpest published difference between them — and in Canada it is not a matter of opinion.

The Canadian Construction Materials Centre, part of the National Research Council, publishes code-compliance evaluations that most authorities having jurisdiction accept as evidence for a product. Each one carries conditions of use. The three reports below cover named products and profiles; they do not cover every board sold under each brand.

Three practical consequences for an Ontario homeowner:

1. A composite deck built in the cold is built with visible end gaps. Eight millimetres at a butt joint looks wrong to an owner who has only seen finished summer photos. It is the requirement, and the gap closes as the boards warm.
2. Late-season builds have a floor. CCMC 13125-R prohibits installation below −9 °C for the Trex products it covers. Check the current instructions and evaluation for the exact board. If a November or March start is being discussed, ask which product is going down and what its cold limit is before the deposit.
3. The PVC numbers are much smaller, and that is a design difference, not a free pass. Cellular PVC still expands and contracts; the manufacturer's method is to hold the boards with top-down fasteners so the movement is distributed rather than concentrated in a joint.

One conflict worth naming. TimberTech's own US installation guide for Advanced PVC says to "install PVC deck boards ends tight together" and to leave no gap at butt joints, splices or mitres, "regardless of temperature." The Canadian evaluation for the same brand's boards sets a minimum end-to-end gap of 1 mm between 0 °C and 10 °C, and 1.5 mm below 0 °C. These are two different documents written for two different purposes, and it is not our place to resolve them. It is worth asking your installer which one they are building to, and — if a building official is relying on the CCMC report — which one your municipality expects.

The rest of the installation rules, in short

• Joist spacing. The evaluations cap support spacing at 400 mm on centre for the AZEK and Fiberon boards, with a minimum of three joists under every board; Trex's ranges from 300 to 600 mm depending on the profile and thickness. TimberTech's guide adds that any angled or commercial installation drops to 12 in. on centre. A 45-degree deck pattern is a framing decision before it is an aesthetic one.
• Width gaps. 3–6 mm for the PVC boards, a minimum 4.7 mm for Fiberon composite, 5 mm for Trex. These are what keeps the deck draining.
• Airflow. Where air cannot move under the deck — roof decks, over water-management membranes, tight skirting, on-grade builds — TimberTech requires at least 1½ in. of clearance and warns that obstructed airflow raises heat build, "which can lead to increased expansion and contraction/gapping."
• Fasteners. Both evaluations require corrosion-protected or stainless fasteners. The PVC guide additionally rules out nails entirely and recommends top-down fastening.

Traction, marks and what the deck asks of you

No decking is slip-proof, and the marketing on both sides invites you to think otherwise. TimberTech markets its Advanced PVC as offering "up to 40% better traction than leading competitor," which is a comparative claim against an unnamed product rather than a safety rating.

The Canadian evaluations publish measured slip indices against a ≥ 0.5 criterion, and they are more interesting reading:

Read those as three separate reports on three separate products, issued on different dates — not as proof that PVC is safe and composite is not. What they do justify is treating stairs as their own problem on any material, and not assuming the surface texture you liked in a showroom behaves the same wet.

Winter, and the cleaning that differs

TimberTech's 2026 care guide covers both materials and is worth following whichever you buy:

• Decking "may become slippery in freezing weather" — the manufacturer's own words, for both materials.
• For ice, most calcium-chloride products can be used; they may leave a white residue to be rinsed off when it is safe to do so. Avoid rock salt and other abrasive ice melts.
• For snow, use an all-plastic shovel. A metal shovel or a plastic one with a metal edge will damage the surface.
• The brushes are not interchangeable: a stiff natural-fibre brush for Advanced PVC, a medium-to-stiff nylon brush for Composite. The guide explicitly warns against using the stiff natural-fibre brush on composite, "as it can dull the surface."
• A pressure washer is for rinsing only — fan tip, maximum 1,500 psi, spraying with the grain.

Neither material is oiled, stained or sealed, and applying a coating can put the warranty at risk. Our deck oils and stains guide covers where that line falls and why it catches people who move from a wood deck.

What the warranties actually say

Warranty length is the weakest way to separate the two materials, because the top of both ranges is now the same.

Fiberon's premium composite now carries the same advertised terms as its two PVC lines. That single row is the clearest evidence that warranty length tracks collection tier, not material.

Warranty is not service life. Coverage, proration, exclusions and any separate labour programme depend on the collection and purchase date. Compare the actual warranty documents in our TimberTech and Fiberon guides. Keep the invoice and confirm whether the proposed use is covered, particularly near water.

Which one for your project

For an Ontario purchase, start with the PVC and composite collections listed by Composite Deck Shop. A line appearing on a manufacturer’s US website does not establish Canadian availability: Trex Refuge, for example, was not listed in the CDS catalogue checked in September 2026.

For the brand-level detail behind these families, our TimberTech guide covers the Advanced PVC and Composite split collection by collection, the Fiberon guide covers its PVC and PE lines, and Fiberon vs Trex compares two composite ranges head to head. The composite decking hub is the starting point if you have not narrowed to a brand yet, and the decking materials hub is the one above that, where PVC and composite sit beside wood and pressure-treated. If the synthetic side is not settled at all yet, wood against composite over ten years is the question one level up from this one.

Common questions

Useful sources

Manufacturer collections, warranty documents and code-compliance evaluations are all revised on their own schedules. Open the sources below and confirm against the exact product and purchase date before you commit.

• CCMC 13690-R — AZEK Deck (Harvest, Vintage), National Research Council Canada: the PVC composition and capping description, the 1 mm and 1.5 mm end-gap conditions, the 3–6 mm width gap, 400 mm joist spacing and the published slip results.
• CCMC 13125-R — Trex decking: the composite composition, the 8 mm, 6 mm and 4 mm end gaps by temperature, the −9 °C installation limit, support spacing by profile and the slip results with their caution.
• CCMC 13500-R — Fiberon decking: the HDPE and sawdust composition, the 4.7 mm, 3.1 mm and 1.5 mm end gaps, the width gap, the stair-tread slip-strip requirement and the note that composite creep exceeds that of lumber.
• TimberTech decking overview and its performance claims page: the zero-wood-filler and wood-flour descriptions, cap coverage, the 30 °F cooler claim with its footnote, the internal 49-day moisture test method, the ASTM D7032 and G154 fade-test basis, warranty ranges and the price tiers quoted above.
• TimberTech Advanced PVC installation guide and TimberTech Composite installation guide (PDFs): the tight-butt-joint instruction, the imperial gapping table, joist spacing including angled installations, the 1½ in. airflow clearance and the Low-E glass warning.
• TimberTech Care and Cleaning Guide, 2026 (PDF): the freezing-weather slip warning, calcium-chloride and rock-salt guidance, the all-plastic shovel rule, the different brushes by material and the tannin/extractive-bleeding note.
• Fiberon Paramount PVC decking and Fiberon on what PVC decking is: the water-contact testing, the freeze-thaw removal instruction, the no-organic-content statement and the cap-coverage wording quoted above.
• Trex decking products and Trex Refuge: the line-by-line warranty terms, the 95% recycled-content claim and the Class A, region-limited PVC line.
• Composite Deck Shop — PVC decking and composite decking collections: the live board prices, colours and lengths in the price section.

This guide is practical public information, not engineering advice or a product approval. A CCMC evaluation is evidence a building official may accept for a product within its own conditions of use; your municipality and the current manufacturer instructions govern your deck.