We Know Wood! Our Guide to Timber

All you need to know about wood and timber before buying fencing, outdoor furniture or wooden decking.

What are the different types of wood? 
Wood is the best wood to use for most products in the garden, a mixture of spruce and larch, ours comes mainly from Scotland. We know that in the sawmill, this mix gives a clean cut, a better-looking natural finish that is more stable. Other types of timber can produce twisted fencing which won't last as long or look as good.

Hardwood is usually made of cherry and maple. It's a high-quality wood which could be grown for as long as 200 years old and usually used for flooring and furniture rather than fencing. AVS sell long-lasting sleepers and the sturdiest and most reliable of gates in hardwood. Our oak sleepers come from France as the slightly warmer and drier climate means oak well there.

Where does our wood come from?
Our wood is slow-grown, meaning it takes about 30 years to grow, making it stronger and more solid. Longer-grown wood will also give a straighter, better cut when it's made into a fencing, decking or any other wooden product, meaning whatever you buy looks better and lasts longer.

We know where all our wood comes from. AVS can tell you the customer the forest it came from, when it was cut down and even the name of the person who cut it down (if the customer wants!)

How can I know if wood is sustainable? 
A huge 90% of our wood comes from England, Scotland and Ireland. Sustainable wood, for us, means the forests have a one-in, one-out policy. For every tree that's cut down, another one (at least) is planted. That's why we're registered with, and monitored by, the Forestry Stewardship Council.

UC3 or UC4?
Many wooden products are referred to as UC3 or UC4. There are four classes of treated timber, from 1 and 2 being the least resilient and ideal for interior use only. UC4 is the longest lasting, the best protected and best suited for outdoor use.

UC3 timber is made to be exposed to the weather but not in direct contact with soil: will last 2-3 years mainly as they're going to be used in the ground and this is more wearing.

UC4 means its treated so the treatment penetrates right down to the core and the sapwood around it will. Life expectancy is of 15 years.

What to look for when buying
All our reclaimed sleepers are Grade A which means there's less defects and damage to them. Grade C ones have chunks out of them and are more likely to be split. They come mostly from France, from old railways and will have a creosote finish. This creosote is highly unlikely to affect the soil or cause any damage by the time it gets to the customer however there are still strict rules around who can handle it.

Fence panels come with frames meaning they have a frame of timber around the entire product, which cheaper ones that will be blown over easily won't. The number of batons running down the fence is also important: we have five on one side and three on the other. Cheaper panels will have three on each side or three and two.

Green vs brown: which is best?
Green wood is a by-product of the timber being pressure impregnated with a wood preservative that is copper-based. The copper reacts with the air to make the timber green. This will extend the life of the timber by up to 15 years. Tanalised timber will change colour over time, firstly to a honey-brown colour, and then a slivery grey.

Brown wood is achieved by adding brown dye to the wood preservative. colour we add a brown dye to the chemical mix. This gives the wood a traditional brown look.

Dip-treated panels vs pressure-treated wood
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. However, dip treatment does not last quite as long and may require additional applications of preservative in order to give the timber the longest life possible.

Pressure treatment is a method that forces preservatives into the timber, right through to the middle. It’s done by putting the timber in a vacuum and then large amounts of pressure applied to force the chemical preservatives in. These preservatives are highly effective against insects and fungal decay. However, pressure treated timber will, on average, last a bit longer than dip treated.

11th Sep 2019