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When choosing a timber for outdoor applications, the more you know the better. Knowledge helps you separate unsuitable species from the right picks, and lays the groundwork for a long-lasting timber product which is fit for purpose. The good news? We have the facts you need to get started.

Learn more about how to find the right timber species for your outdoor project with these pointers.

Hardwoods Are not Always Hard

Thinking that all hardwoods are going to be super tough is, unfortunately, a mistake. While there are many durable, strong hardwood species out there, you can also find hardwoods which are on the softer side, e.g. Balsa, or that are not suitable for outdoor use. On the other hand, softwood timbers can sometimes be really tough. Western Red Cedar and Larch, for instance, are two softwoods that are very durable and perform well in many outdoor applications.

The moral of the story? Do not judge all timber species by whether they are labelled hardwood or softwood.

Not All Durable Timbers Can be in Ground contact

While there are plenty of durable timber species you can choose for outdoor use, not all of them are suitable for the same applications. In particular, you need to know the difference between outdoor use and ground contact use. When building decking, for instance, any timber which comes into contact with the ground needs to be extremely durable, with excellent resistance to rot.

A great example here is Oak. While we love using untreated Oak for many outdoor applications, it is not always best-suited for long-term ground contact. Ipe and Ekki, on the other hand, will withstand ground contact with ease.

Outdoor Projects Need Use Class 3–5 Timber

Following on from the previous point, one of the easiest mistakes to make when choosing timber for outdoor use is ignoring Use Classes. These classifications exist for a reason: they tell you exactly how much moisture exposure a piece of timber can handle before things start going wrong.

Use Class 3 is going to be your baseline for outdoor above-ground applications, such as cladding, decking or benches. Move into areas where timber sits on or very close to the ground, and you are firmly into Use Class 4 territory, and if you are building something which will be permanently in contact with water, you will need Use Class 5.

Moisture Movement Can Make or Break Your Project

Different timber species handle moisture in very different ways, and this matters a lot outdoors. Some timbers stay super stable as humidity and weather conditions change, while others expand and contract if they take on (or release) too much moisture too quickly. This is particularly important if you are choosing a timber species for cladding or decking, where movement can cause gaps.

Species such as Cedar and Iroko are naturally dimensionally stable, making them ideal choices. Other timbers may still be durable, but need careful maintenance and installation to keep movement under control.

Timber Can Lose its Colour Outdoors

No matter how tough a timber species is, sunlight will always win the colour battle eventually. UV exposure breaks down the timber’s surface fibres, causing even the richest, most vibrant timbers to fade to a silvery grey over time.

Some people love that weathered look, while others prefer to maintain the original colour of their timber. If you fall into the latter group, you will need to apply a suitable UV-protective treatment to prevent fading.

Remember, though, that fading is not a flaw, and it is definitely not a sign that your outdoor timber is damaged.

Speak to Our Experts

There is a lot to consider when choosing a timber species for outdoor use. Feeling a bit overwhelmed? We’ve got you. Our timber experts at EcoChoice would be happy to talk more about your options and find the right timber species for your project.

Get in touch today.

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Our timber experts have years of experience and will be able to match the perfect species to your project, as well as provide a quote for sustainable timber at highly competitive prices.

Frequently asked questions

Do you supply timber for domestic uses?

Yes, we supply timber for domestic applications as well as commercial and public constructions. From garden decking to shed cladding, we will be happy to supply smaller deliveries for home use.

Is your timber FSC-certified?

Yes, all timber we supply is FSC or PEFC certified and sourced from independently verified responsibly managed forests. If we can’t find your request in FSC/PEFC certified timber we’ll suggest an alternative that is certified or clearly note that the offer is minimum EUTR.

Where does EcoChoice deliver to?

EcoChoice delivers to construction sites, warehouses and homes across the UK, as long as there’s access and unloading for our trucks.

What are the best timber species for exterior use?

There are many different timber species suitable for exterior use and which is the best for your project depends on your requirements. In general, though, we recommend EkkiGreenheartOpepe and Oak for heavier civil/marine uses. For intermediary external use such as decking, where the timber needs to be both strong and durable but not on the same level as civil engineering (bridgespiling, etc) we usually supply CumaruIpe, Jatoba, and Balau. And for the lighter exterior use where the timber is non-structural such as cladding, we deliver CedarLarchThermowood and others.

Which timber is the most durable?

Durability Class 1 timbers are the most durable. This of course depends on the use (hazard) class they’ll be in service for. For direct ground and water contact such as sleepers, fenders, marine piling, etc, Ekki and Greenheart are known to be the most durable timbers available. For decking and cladding where there’s no direct ground contact (use class 3) there’s a much wider range of timbers such Larch, Cedar, Thermo modified Pine or Ash and others.

What’s the best timber for internal cladding?

Internal cladding, where your timber is not in ground and not exposed to the elements can be classed as either use-class 1 or 2 – in which case most timbers will meet this durability criteria. That is not to say they’ll be the best, since internal environments have lower humidity (moisture) levels than outside. So in these cases, it’s best to go for a kiln-dried timber cladding board as these are more stable and delivered already in lower MC (moisture content) than the usual fresh sawn timbers sent to external applications. A word of caution – as timber reacts to variations in moisture, it’s best to avoid cladding any areas inside your bathroom.

How can I make decking less slippery?

The first thing is to ensure your deck boards are kept clean from leaves and other debris which will, over time, cover the surface and make it more slippery. Grooved boards can be used to improve grip if installed and used perpendicular to traffic, so especially useful in narrow passages and footbridges. Lastly, you can add our Grip-Choice strips: these are a mix of epoxy with aggregates that add gripping ridges to your deck area. Gripchoice is an easy way to make decking less slippery and safer, especially over large areas or where there’s high traffic. We can pre-install Grip-Choice strips for your decking before delivery or ship the strips separately to add to your existing deck’s grooves as a retro-fit solution.

What wood machining services do you offer?

We can offer planing, sawing, drilling and profiling of rough-sawn wood to any profile you require: from handrails to large port fenders.

Can you supply pre-drilled timber?

Yes, we will be happy to provide pre-drilled timber which is tailored to your needs for quick installation, thus saving you valuable time on site.

What cladding profiles do you supply?

We provide a wide range of cladding profiles, including tongue and groove, featheredge and shiplap. You can check the standard profiles here – but we can also match or custom make profiles to suit your specific needs.

Does timber change colour?

Yes, timber is well-known for changing colour over time. Some species can darken quickly right after installation, and like most untreated wood will eventually weather to a beautiful silver-grey. Interior timber is less likely to change colour (depending on conditions), and timber can be stained, painted or treated with UV-resistant oils to reduce colour change.

Do I need to treat exterior timber?

Some timbers such as Oak and Ekki, can withstand the strains of exterior use without any treatment. However, to extend the lifespan and maintain the aesthetic of your wood, we do recommend treating your timber with stains and oils. Pre-treated timber, such as ThermoWood and OrganoWood, are low-maintenance options which are more durable, but can have their life service extended by applying a clean and stain maintenance schedule.

Do I need to treat interior timber?

Depends on what area the timber is being used. For floor joists and timber rafters, it is common to see timber treated, or least very well kiln-dried. Other uses such as flooring may benefit from varnishing while internal timber cladding for decorative purposes shouldn’t require any treatment other than if you want to change its colour with different types of stains or oils.

Where are you based?

We’re based in Cambridge, UK, and coordinate multiple sawmills all over the world to manufacture your order. We then organise delivery with a range of hauliers so that your orders gets to your site on time.

What are the usual decking sizes?

Timber decking is usually 21x140mm or similar. For heavier applications where there’s more load and traffic, we deliver 35 or 45mm thick boards (such as Hastings Pier). Narrower boards are also possible: 95-90mm is a standard width – but we can manufacture whatever size you require.

What are the usual cladding sizes?

Typical cladding section sizes are 18×95 and 18x145mm although we can always custom make a section to suit your project’s design requirements. That includes waney edge boards in Oak or Chestnut as well as extra wide 195mm boards.

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Good quality, great service, fast delivery!

5

Marinella Li

Always helpful! One of our valued TDCA DeckMark and CladMark accredited supplier members which means their quality procedures are routinely audited and stand up to scrutiny giving you extra peace of mind.

5

Janet Sycamore

Having needed the supply of cladding, decking boards and other specified timbers through out the year Eco choice have been very helpful in sourcing the specified timbers and quantities required at a very competitive price.

5

Tim Saunders

Great quality, service and price. A pleasure to deal with. I would highly recommend Eco Choice.

5

Emma Hurrell

Fantastic company- Mike and the team are the best in the business- worked with them for many years.

5

Prem Raja

Always reliable and quality products, easy to deal with company.

5

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Average rating on Google Reviews

  • 9 years ago

Excellent service and outstanding product

Cindy Dicks

  • 6 years ago

Having needed the supply of cladding, decking boards and other specified timbers through out the year Eco choice have been very helpful in sourcing the specified timbers and quantities required at a very competitive price.

Tim Saunders

  • 6 years ago

Fantastic company- Mike and the team are the best in the business- worked with them for many years.

Prem Raja

  • 9 years ago

Experts in Timber, Nationwide delivery

Joe Middleton

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