Composite vs Timber Decking — UK Cost & Performance
A detailed comparison of composite and timber decking boards for UK gardens — covering cost, maintenance, durability, appearance and environmental impact.
Side-by-Side Comparison
| Property | Composite | Softwood Timber | Hardwood Timber |
|---|---|---|---|
| Supply cost per m² | £40-80 | £15-30 | £40-70 |
| Installed cost per m² | £60-100 | £30-60 | £60-100 |
| Lifespan | 25-30 years | 10-15 years | 20-30 years |
| Annual maintenance | Jet wash once a year | Sand, oil/stain annually | Oil 1-2 times/year |
| Maintenance cost/year | Minimal (£0-1/m²) | £3-5/m² | £2-4/m² |
| Rot resistance | Immune | Poor without treatment | Good (naturally) |
| Colour fade | Slight in first year, then stable | Greys without treatment | Silvers naturally |
| Thermal expansion | Significant — needs gaps | Minimal | Minimal |
| Heat retention | Gets hot in sun | Stays cooler | Stays cooler |
| Splinters | None | Common | Rare |
Pros and Cons
Composite Decking
Pros
- + No annual sanding or staining needed
- + Will not rot, warp or splinter
- + Consistent colour and finish
- + 25-year manufacturer warranties
- + Lower lifetime cost than softwood
Cons
- - Higher upfront cost
- - Gets hot in direct sun
- - Cannot be sanded or refinished
- - Looks less natural than real wood
- - Thermal expansion needs careful spacing
Timber Decking
Pros
- + Lower upfront cost (softwood)
- + Natural look and feel
- + Stays cooler in sun
- + Can be sanded and refinished
- + Easier to cut and work with
Cons
- - Annual maintenance required
- - Softwood rots without treatment
- - Splinters develop over time
- - Shorter lifespan (softwood)
- - Ongoing maintenance costs add up
UK Cost Comparison (2026 Prices)
For a typical 20 m² UK garden deck (4m x 5m):
| Cost Element | Composite | Softwood | Hardwood |
|---|---|---|---|
| Materials | £1,200-1,600 | £400-600 | £800-1,400 |
| Subframe (treated timber) | £200-300 | £200-300 | £200-300 |
| Fixings & clips | £100-150 | £30-50 | £50-80 |
| Labour (2 days) | £400-600 | £400-600 | £400-600 |
| Total installed | £1,900-2,650 | £1,030-1,550 | £1,450-2,380 |
| Maintenance over 20 years | ~£200 | £1,200-2,000 | £800-1,600 |
| 20-year total cost | £2,100-2,850 | £2,230-3,550 | £2,250-3,980 |
When to Choose Each
Choose Composite When
- You want minimal ongoing maintenance
- You have young children (no splinters)
- The deck is in a shaded or sheltered area
- You are planning to stay long-term
- Budget allows higher upfront spend
Choose Timber When
- Budget is tight (softwood is half the price)
- You want a natural wood appearance
- The deck gets strong afternoon sun
- You enjoy or do not mind annual upkeep
- You may want to sand and change the colour later
Environmental Considerations
Timber decking from FSC-certified UK-grown softwood has a lower carbon footprint at manufacture. However, the preservative treatments (tanalising) and annual staining products contain chemicals. Composite decking uses recycled wood fibres and plastic, diverting waste from landfill, but is not biodegradable and is difficult to recycle at end of life. Hardwood decking (especially tropical species like ipe) has significant transport emissions and deforestation concerns unless FSC-certified.
Related Calculators
- Decking Calculator — calculate boards and joists for any deck size
- Composite Decking Calculator — material quantities for composite boards with hidden fixings
How We Calculate This
Frequently Asked Questions
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Last updated: April 2026
All calculations are estimates. Verify with your supplier.