​What's the Difference Between Green and Brown Timber?

We sell both green and brown timber, but what does that mean and which timber is best for your gardening project? Here's all you need to know on how we treat the wood that make up our products

What is green timber?
The naturally-pale, wooden colour of green timber also has a slight green tint or fleck due to the chemicals used in the pressure-treating process 

What's brown timber?
In comparison, brown timber is a darker colour of wood which has been stained on treatment. At AVS, brown timber can be either pressure-treated or dip-treated.

How is timber pressure-treated?
Pressure-treating timber (whether brown or green) helps give it a longer lifespan by guarding against infestation of insects, mould and fungus as well as the rot caused by the extremes of the British weather.

How does it work?
Untreated timber is put into the treatment tank which is then sealed and flooded with chemicals (ACQ), the tank is put under pressure to force the treatment into the timber as far as possible. The tank is then emptied of chemicals and the timber left to dry.

This process gives it a longer lifespan – extending the expected life by up to some 15 years. Some types of timber absorb more treatment than others but all pressure-treated timber is unlikely to absorb water once installed.

The chemicals used in pressure treatment are copper based which can react with the sap of the timber or air and this is what creates green flecks on the surface.

If the timber is brown pressure treated it goes through the same process as green but an additional dye added to the treatment.

How is wood dip-treated?
Products that are dip treated brown have been dipped in a tank with the preservative and then taken out to dry. Dip-treated products will have a shorter lifespan than those that are pressure-treated which is why we only supply dip-treated panels and trellis – products that shouldn't be in contact with the ground which means they degrade faster.

Dip-treated wood is often a darker brown or golden colour. The dip-treating process is fairly quick to carry out, meaning it's often more cost-effective than pressure-treated wood.

How do I care for pressure-treated timber?
Over time, the colour of fencing will change firstly to a golden brown and then a silvery grey. If you want to choose your own look, both green and brown timber can be painted or stained a different colour (this will also give it another layer of protection). If you're choosing to paint pressure-treated wood a different colour, do treat it first to seal it. And always read the treatment instructions carefully.

How do I care for dip-treated timber?
Dip-treated wood does not last quite as long as pressure-treated wood and may require additional applications of preservative in order to give the timber the longest life possible

Help & advice
If you need more information about fencing and landscaping, please get in touch with your local branch. Our specialists will be happy to offer help and advice and can provide you with a free quote for supply of all relevant materials.

19th Nov 2019