Does composite decking get too hot in Adelaide?

Dark composite boards can hit 60-70°C surface temperature in full Adelaide summer sun — hot enough to be uncomfortable barefoot. Choose pale grey or beige composite for full-sun locations. Timber stays 15-20°C cooler in the same conditions.

How long does merbau decking last in Adelaide?

Properly installed merbau on an H3-treated pine or steel sub-frame with annual oiling lasts 20-25 years in Adelaide conditions. Without maintenance, expect grey-weathering within 12 months and structural failure within 8-12 years.

Do I need to seal composite decking?

No. Quality composite decking (Modwood, Trex, Ekodeck) is designed to be maintenance-free. Just hose it down annually and clean occasional stains with warm soapy water. Never seal or oil — it voids the warranty.

What is the best decking for around an Adelaide pool?

Composite wins around pools. Chlorine and salt water accelerate timber decay and cause staining. Composite handles wet feet, sunscreen and pool chemicals without any special maintenance. Pale-coloured composite also stays cooler underfoot for barefoot pool users.

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Decision Guide

Timber vs Composite Decking in Adelaide

Which material actually suits your backyard?

Composite decking now outsells timber in most Adelaide postcodes because homeowners are sick of oiling merbau every summer. But composite has its own trade-offs — heat retention in direct sun, a huge quality gap between $180 and $520 per m² ranges, and a very different aesthetic. This guide is the honest comparison on cost, longevity, heat and maintenance for Adelaide conditions.

Timber Decking (Merbau / Spotted Gum / Blackbutt)

Pros

Cheaper upfront — merbau installed from $310/m²
Cooler underfoot in direct sun (15-20°C cooler than composite)
Natural material — ages with character
Can be sanded and refinished if damaged
Australian hardwoods (spotted gum, blackbutt) are highly durable
Works better in shaded / south-facing decks

Cons

Annual re-oiling required in Adelaide UV
Grey-weathers within 12 months without maintenance
Fixings visible unless secret-fixed (adds cost)
Some warping and cupping expected over time
Merbau leaches red tannins onto light-coloured paving
Termite risk if not H3-treated

Best For

• Shaded or south-facing decks
• Homeowners willing to oil annually
• Traditional / character home aesthetics
• Budget projects using merbau
• Buyers wanting a genuine timber feel underfoot

Composite Decking (Modwood / Ekodeck / Trex)

Pros

Zero annual maintenance
20-25 year manufacturer warranties on quality brands
Doesn't splinter, warp or leach tannins
Consistent colour and grain
Won't rot in Adelaide's wet-winter/dry-summer cycle
Higher resale appeal — buyers see 'maintenance-free'

Cons

Higher upfront cost — $380-$520/m² installed
Gets hot underfoot in direct sun (60-70°C on 38°C days)
Cheap Chinese composite fades and cracks within 3-5 years
Can't be refinished if scratched — must replace boards
Feels less 'natural' underfoot than timber
Some brands fade or chalk in Adelaide UV

Best For

• Full-sun decks where pale composite avoids heat issues
• Homeowners who won't do annual maintenance
• Rental properties and holiday homes
• Long-term resale focus
• Around pools where salt / chlorine damages timber

Cost Comparison per m² Installed (Adelaide Feb 2026)

Common Questions

Over a 20-year period, quality composite (Modwood, Ekodeck, Trex) works out slightly cheaper than merbau timber once you factor in annual oiling costs and eventual board replacement. Australian hardwoods like spotted gum or blackbutt land between the two on lifetime cost.