Plastic, PVC and composite decking compared

Independent comparison. Teosad may earn a commission from some retailer links; this never changes the order or the numbers. Disclosure

What is the difference between PVC and composite decking?

PVC decking is made of plastic with no wood fibre. Composite decking mixes plastic with wood fibre or minerals. The shop words “plastic decking boards”, “artificial decking”, “fake decking” and “synthetic lumber” cover both, which is why it pays to read the material line.

What does a PVC board look like on paper?

Cladco’s Nordeck is the only true PVC board we could read. It’s 3.6 m long, 200 mm wide and 32 mm thick, weighs about 18.2 kg and covers 0.7 m², at £66.68 including VAT, about £95.26 per m² before the frame. Cladco says it has no wood fibres, the description gives a 20 year structural, stain and fade warranty, and its warranty table gives 15 years plus 5 residential, with the extra 5 years conditional on Cladco plastic joists and registration. Cladco’s installation guide asks for joists at 300 mm centres, doubled where board ends meet, a gap of at least 3 mm to the next board and to fixed objects, a 47 mm airflow gap in poorly ventilated areas, and pressure washing at 2,000 psi or less.

Eva-Last’s Apex technical data sheet gives a coefficient of thermal expansion of 46.2 by ten to the minus six per degree, a fire class of Bfl-s1 for its single-cap profile and reports wet pendulum slip tests.

Is PVC hotter or cooler, lighter or heavier, than composite?

No maker we read compares the two on weight, heat or expansion. What each does say:

• Heat: Cladco says Nordeck boards can become hot over prolonged periods and darker colours feel hotter in sun.
• Slip: Millboard’s article says PVC slip resistance varies by brand, so check the boards you choose. Cladco describes Nordeck as low-slip.
• Water: Cladco says Nordeck is more durable and completely water-resistant, while composite is more eco-friendly and cost-effective.
• Cost and life: eDecks says PVC is all plastic, lightweight and lasts up to 25 years, and calls composite better for slip resistance and less likely to warp or expand in extreme weather. That is a retailer’s view with no numbers.

For composite weights, EnviroBuild gives hollow boards at 2.5 to 3.5 kg per metre and solid at 4.5 to 6. Cladco’s Nordeck works out at about 5.1 kg per metre, from its listed figures.

How do you tell what you are buying?

Read the maker’s material line, not the shop’s category. Truly PVC and Eurocell sell a “hollow decking” board, 145 by 25 by 3,660 mm with a 20 year warranty and joist centres of 350 mm, that is a 60 percent recycled wood and plastic composite. We don’t treat it as PVC. See our boards comparison for composite boards, and the prices page for what they cost.