Living in a coastal area, outdoor timber cops it. It’s the air, always damp from constant rain and laden with salt borne ferocious gusts that shake fixings and joints.
Choosing the right type of timber for a fence is one thing, but if you fail to finish that material properly, your fencing could begin splitting, warping or becoming loose after just a single winter.
So, what is it about the coast that can cause such havoc to timber?
Timber can swell, move or become mouldy if dried too slowly in high humidity.
Salt spray attacks screws, nails and brackets (shallow rusty stains on timber, joints weakened)
Post, rail and gate load must cater for wind loading. For advice from Timber Merchants Portsmouth, visit www.timbco.co.uk/timber-merchants-portsmouth/
Over time, UV exposure (especially in open coastal areas) will break down the surface fibres and fade finishes. Which means that you are not just choosing wood – but a system, timber plus treatment plus fixings and finish.
Top picks for coastal decking
Softwood, pressure-treated (Good value; popular)
Pressure-treated softwood is typically the sensible option for fencing, decking frame work, sleepers and easy garden builds. Specify ground contact treated timber (decking) when applicable (posts, sleepers etc… anything coming in to direct with soil). While it already resists rot, treatment also adds possible benefits if a protective finish is applied.
Naturally durable hardwoods (premium durability)
Solid hardwoods are the best exterior grade woods to use for outdoor projects such as decking, but not all offer equal performance. Although hardwoods are usually denser and potentially tougher, they still swell with moisture change, so they too will need the correct fixings.
Modified timber (stability-focused)
This timber is specifically designed for increased sturdiness and durability in specific projects. If you are more concerned about movement and length of service, then talk to your timber merchant about an option that is designed for external performance.
Don’t overlook fixings and finishes
Coastal: the wood actually fails before some screws in coastal areas where you are more likely to need stainless steel or bronze fasteners than marine grade galvanized.
Rustproof fixings rated for outdoor/coastal use
Do not mix metals as it can interact with other metal parts and increase corrosion
Seal the cut ends, and apply an external wood stain / paint/ oil to retard moisture changes
Use good drainage and airflow (timber does well when it can dry out).
The takeaway
In the case of most coastal properties, pressure-treated timber plus screws and finish carefully selected give cost versus life expectancy with a favourable ratio.