Timber preservation – withstanding the winter

Treating timber, particularly softwood, with preservatives, or putting it through specially designed industrial processes, can significantly extend its lifespan.

This is especially true when the timber is used in outdoor installations. The type of treatment used on the wood as well as their specific environment will determine how long it will last in the great outdoors. Different processes offer different protections, so it’s important to find out exactly how your wood has been treated before you buy.

Understanding the preservation processes used to treat timber will help you to find the right method, and the right products, for your build. Keep reading to find out more.

Is your timber already treated?

If you’re buying exterior softwood timber from a specialist trade supplier, there’s a very good chance that the wood has already been treated in order to extend its lifespan. As @TDCAJanet says, “Much of the decking and landscaping timber available through trade suppliers has already been treated in this way, but to varying levels of protection.”

The treatments that manufacturers use will vary depending on the intended end use of the timber. Wood that will come into contact with the ground needs to be especially tough and resilient, while decking that will be suspended above the floor doesn’t need to be quite so hardy.

The class system

Decking components made from softwood species that are classified as semi or non-durable must be pressure treated before installation. The treatment used needs to be carefully selected in order to provide the service life required.

The amount of preservative protection required depends on the intended end use of the timber. These end uses are categorised according to a Class System detailed by British/European Standard BS EN 335-1.

Class 3 – End uses that are categorised as Class 3 include timber that will not come into contact with the ground. This covers things like balustrades, deck boards, cladding, and other elements that won’t touch the ground.

Class 4 – Class 4 covers situations where timber will be in contact with the ground or with fresh water. Timber that’s in contact with the ground tends to degrade more quickly, so stronger preservation methods are required.

Timber components that need to meet Class 4 standards include posts, beams, joists, and some deck boards.

Timber treatments

The standard way to add preservatives to softwood timbers going into the use classes 3 and 4 described above is with pressure. Large tanks are loaded with several tons of wood, which is then flooded with the treatment chemical solution. A high pressure system then forces these preservatives deep into the timber, ensuring that they continue to protect the timber long after installation.

Other types include dip treatments and wood preservatives that are applied by brush. These are not as suitable for the long-term protection of timber used for decking and outdoor landscaping since they don’t penetrate as deep into the wood.

Using improperly treated timber will significantly shorten the lifespan of your installation, so it’s important to check that the wood you buy is up to standard.

The preservative product generally used for outdoor timber is described as copper organic. One of the most commonly used examples of this is TANALITH. Wood that’s been treated with TANALITH is known as tanalised timber and has a soft green/brown colour. Over time, this will change to a silvery grey hue. There are other similar alternatives such as MicroPro.

Products can be added to the treatment to colour the wood and to provide further protection from the elements.

Find out more about preserving wood for outdoor use, and learn about the durable, sustainable products we offer, by exploring our site today.

Tips on preserving timber during winter

Ask Joe! Expert industry advice

Unsure which timer is best for your project?

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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What our customers say about us

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

Stone Zone

4.9

Average rating on Google Reviews

  • 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

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

  • 2 weeks ago

Good quality, great service, fast delivery!

Marinella Li

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