I'm Alfie Jaques, a City & Guilds-qualified carpenter based in Bournemouth (BH2), and I cover Poole, Christchurch and the surrounding 10-mile radius. I cut joints into the frame rather than laying boards on top and screwing them down, and every quote is written and itemised before any work starts.
Composite versus timber is the live decision on nearly every decking quote in this trade, and the honest answer depends on where the garden sits, not a blanket rule. Three local factors change the calculation: salt-laden coastal wind, how much shade the garden gets, and what's underneath the grass.
Does salt air change which material makes sense?
Yes … salt-laden south-westerly wind dries and greys exposed timber faster, and corrodes ordinary steel fixings.
Gardens within around a mile of the shoreline, Sandbanks, Southbourne and the Alum Chine area among them, sit in wind carrying enough sea-salt aerosol to dry and grey exposed timber faster than an inland garden, and to corrode standard steel fixings over time. That's why marine-grade stainless fixings and a capped composite board hold up better than bare softwood right on the coast. Further inland, in Talbot Woods or Charminster, the same choice becomes more of an upfront-cost-versus-upkeep question than a durability one.
Which handles a shaded, damp garden better?
A capped composite surface generally sheds surface moisture and algae growth more easily than untreated softwood left in shade.
The Met Office's nearest official station, Hurn, averages around 877mm of rain a year across 1991–2020, with November the wettest month at roughly 108mm. In a shaded, north-facing garden, or one sitting under mature tree canopy, that moisture sits on the boards for longer between dry spells, and timber left untreated in shade is more prone to green algae growth than a sealed composite surface. My own read on the trade-off: composite drains better and absorbs less water, so it's less likely to expand, rot or break down over time than an untreated board left in a damp corner.
Does the ground itself affect the choice?
Yes, though it affects the frame and footings more than the board material … see the dedicated guide on Poole’s clay soil for the detail.
Bournemouth and Poole sit on laterally variable ground: free-draining sandy heathland-fringe soil around Canford Heath and Talbot Heath, alternating sharply with clay layers, and more London Clay-influenced soil surfacing further inland around Talbot Woods and Charminster. British Geological Survey mapping under-cuts any simple suburb-by-suburb rule, so the ground gets screened at the address rather than assumed from the postcode. Clay swells and shrinks with the seasons, which is a foundation question rather than a board-material one. See the Poole clay soil guide for how that’s handled. Chine-side and cliff-top gardens (Alum, Middle, Durley and Boscombe chines, and the West Cliff/East Cliff frontage) tend to step down a steep gradient rather than sitting flat, which usually calls for a raised deck on engineered footings whichever board material is chosen.
Composite vs timber, at a glance
| Composite (capped) | Timber (softwood/hardwood) | |
|---|---|---|
| Look | Consistent, modern finish | Natural grain, warms with age |
| Ongoing upkeep | Brush and wash | Needs periodic treating/staining |
| Moisture handling | Drains well, low water absorption | Absorbs more water if untreated |
| Coastal salt exposure | Holds colour and shape better close to the shoreline | Greys and dries faster in salt-laden wind |
| Shaded/damp gardens | Less prone to surface algae build-up | More prone to green algae if untreated |
| Fixings needed near the coast | Marine-grade stainless recommended either way | Marine-grade stainless recommended either way |
No figure in this table is a price. Every quote I give is written and itemised against your actual garden, so get in touch for a real comparison rather than a generic one.