Why Pressure Treated Wood Makes the Best Garden Furniture

You have a lot of choices when it comes to garden furniture—hardwood, softwood, metal, plastic and rattan to name just a few—and each has its own advantages and disadvantages. Hardwood for example is extremely durable (they used it in the old days to build ships) and it looks great (it's also used to make fine furniture)—but it's heavy and expensive. Plastic furniture on the other hand is very affordable and light in weight, but it looks cheap and nasty and doesn't last.

There is however one superstar material that is often overlooked, that achieves an impressive balance between cost, aesthetics, durability and sustainability—pressure treated softwood.

What does pressure treated mean?

Softwoods—such as pine, cedar and birch—require some sort of treatment and protection before they can be used for construction or furniture. Without it, they would be susceptible to rot and decay.

The traditional way to treat softwood is dip treatment. This process involves taking a piece of timber and literally dipping it into a tank full of preservative chemicals. The problem is that the preserving agents only coat the surface of the wood—all it takes is one little scratch or dent to expose the untreated wood underneath. Dip treatment is often used on cheaper fence panels and furniture.

The better alternative to dip treatment is pressure treatment. Pressure treatment uses a high pressure vacuum tank to force the preservative agents deep into the structure of the wood. The wood is protected all the way down to its core, making it far more durable and resistant to rot.

Pressure treated timber is sometimes referred to as "tanalised" timber. The two phrases mean the same thing.

Why not just use hardwood?

Hardwoods such as oak, elm and teak contain naturally occurring oils which protect the wood from rot without the need for treatment. So why would you spend all that time and effort treating softwood if hardwood is already naturally durable?

Two reasons—weight and cost.

Hardwood is significantly heavier than softwood. This causes a number of problems—it's more expensive to transport, it's more difficult to cut and work with, and it's harder work to assemble hardwood garden furniture.

Hardwood trees are grown in tropical parts of the world, which drives up the cost if you live somewhere like northern Europe. It also takes longer to dry once it's been cut down, further increasing the cost. Finally, hardwood comes from slow-growing trees, which means longer production times and (you guessed it) a higher price-tag.

Softwood, on the other hand, is lighter in weight, cheaper to buy, and more sustainable to produce.

How long does it last?

There's no denying that hardwood furniture does last longer than softwood, especially when it's outside and exposed to the elements. That's why it's often used for things like shipbuilding, barrels, flooring and heavy-duty construction. Hardwood garden furniture can last for several decades without much maintenance.

Softwood isn't quite as durable, but it's no slouch either—just as long as it is pressure treated. It can still last well over a decade. Many manufacturers offer a guarantee of 10-20 years on their pressure treated furniture. It's also commonly used for fence posts, decking and fence panels.

Which looks better?

That's really a matter of opinion, but if you do love the rich, dark colour of hardwood, you can always paint or stain your softwood furniture to achieve the same effect. Another bonus of softwood is that it's very easy to cut and machine into interesting curves and shapes.

Pros & cons of hardwood & softwood

It's our opinion that pressure treated softwood is superior. Hardwood has a slight advantage when it comes to lifespan, but softwood beats it in every other contest. Take a look at this chart from Garden Furniture Land that runs down the pros & cons of both:

Whichever type of wood you go for, look out for the FSC mark to make sure your furniture was sustainably produced.