What is hardwood? In the timber trade, hardwood usually means dense tropical species such as Okan, Azobe and Tali. Their heartwood resists rot, fungi and insects on its own. You can use it outdoors without chemical treatment, even in the ground or in water. That makes it the first choice for posts, decking and bank protection that have to last for decades.
Softwoods such as Douglas fir and larch need treatment, or have to be kept off the ground, to last outdoors. Hardwood does not. Houthandel Jan Sok in Meppel has supplied hardwood of traceable origin since 2000 (KvK 04062841). We serve homeowners, small businesses and contractors, and are rated 4,8 stars from more than 141 reviews.
What hardwood means in practice
Strictly speaking, hardwood comes from broadleaf trees. For outdoor work, what counts is how long the wood lasts. The European standard EN 350 rates the heartwood of each species in classes from 1 (very durable) to 5 (not durable). The tropical species we stock are rated class 1. So they last for many years outdoors without treatment. That includes direct contact with soil or water (use class 4 under EN 335).
Species and durability class
Not all hardwood is the same. We stock three species, each with its own strengths.
- Okan — heartwood class 1, with an expected service life of more than 25 years, including ground contact. Very strong, a good choice for posts, beams and structures in the ground.
- Azobe — heartwood class 1. Heavy and hard, the standard for sheet piling and bank protection in water. Correctly installed, it commonly lasts 25 to 40 years or more, even in ground or fresh-water contact.
- Tali — heartwood class 1, lasting 25 years or more untreated, even in ground or fresh-water contact. A versatile choice for decking and outdoor structures.
Comparing species for a deck? Read Okan vs Tali for decking or our wider decking materials comparison. Each species also has its own guide: what is Okan, what is Tali and what is Azobe.
What hardwood is used for
Hardwood is used where you need a long life and real strength. Think of fence and pergola posts, beams, cladding, decking, and sheet piling or bank protection in water. A hardwood deck typically lasts 25 to 40 years. Okan posts in the ground last more than 25 years. Correctly installed Azobe sheet piling commonly lasts 25 to 40 years or more in water.
Pros and cons
Pros: it lasts 25 years or more without treatment. It can go in the ground or in water, and it is very strong.
Cons: a higher price than softwood, and heavier and harder to work, so you need sharp tools and pre-drilling. Untreated hardwood turns grey over time. That only changes the look, not the strength. Oil can slow the greying if you prefer the original colour.
Wondering whether a cheaper softwood would do? Read hardwood vs Douglas.
Care
Untreated hardwood weathers to a silver-grey tone. This is a surface change and does not weaken the structure. If you want to keep the original colour, apply a hardwood oil once a year. Otherwise, a yearly clean with water and a soft brush to remove algae and dirt is all it needs. That low need for care is one of the main reasons hardwood is chosen for sheet piling and bank protection.
Frequently asked questions
What exactly is hardwood?
In the timber trade, hardwood means dense tropical species such as Okan, Azobe and Tali. They last for a long time outdoors without chemical treatment, even when they stay in soil or water.
How long does hardwood last?
It depends on the species and the use. Decking lasts around 25 to 40 years. Correctly installed Azobe sheet piling commonly lasts 25 to 40 years or more in water. Okan lasts more than 25 years in the ground, and Tali 25 years or more untreated.
Does hardwood need treatment?
No. Hardwood is durable on its own. Oil is optional and only keeps the colour. Untreated, the wood turns grey, which is purely cosmetic.
Which hardwood species do you supply?
Houthandel Jan Sok supplies Okan, Azobe and Tali of traceable origin, as posts, beams, boards, decking and sheet piling. See the hardwood range for sizes in stock.