A pergola can truly make a garden if it survives the UK wind, rain, and movement of the seasons.
Here are a few practical things to keep in mind about pergola timber for the best performance and longevity.
- Best all round – Pressure-treated softwood
Softwood (usually pine or spruce) that has been pressure-treated is ideal for most garden pergolas. This type of deck material is cheap and commonly used outdoors.
Why it works:
Protects against decay and the attack of insects
Easy to cut, drill, and fix
Good strength for the price
Pro Tip: If you are setting any posts in the ground, always request ground contact wood. Otherwise, let the timber dry out and use post supports to keep it off wet soil.
- Douglas fir or larch – Naturally durable
Douglas fir and larch offer the look of a pricier hardwood while keeping within your budget.
Benefits:
Inherently strong, more than regular softwood
Nice grain and colour (usually looks good with a clear oil)
Suitable if properly sized for long spans.
Most of these timbers, being composite, still require sound structures and finishing for protective purposes, especially the cut ends. For Timber Merchants Southampton, visit Timbco.
- Hardwoods (durable but heavy and expensive as well)
Hardwoods lend themselves well to pergolas, especially when you desire a very long-lasting structure and are prepared for the higher price tag. Ask for advice at a Timber Merchants Southampton.
Pros:
Dense and hard-wearing
Finishing on this one really lasts forever.
Considerations:
You will have some heavy lifting and use more energy
Needs pre-drilling for fixings
Hardwoods, more than other building materials, move with changes in the humidity.
Strength and durability tips for (whatever timber you choose)
A pergola is more likely to fail from incorrect design and water traps than the timber.
Size correctly – the posts must be thick enough to support the wind load, and the beams fit as needed.
Use post shoes or concrete bases to keep timbers off the ground.
Trim exposed ends – log cuts are susceptible.
Use the correct fixings: exterior-rated, galvanised, or stainless steel.
Preserve it – re-oil or stain on the sides that you see most often as necessary.
The simple takeaway
Pressure-treated softwood. For most projects, this lumber is the best combination of strength, durability, and cost. Douglas fir or larch is a robust step up for those looking for more of a premium finish. Hardwood is sweet; however, it might be dearer and heavier to hold.
