Hardwood is the group name for tropical timber species that are very dense and hard. You can use them outdoors without chemical treat. Anyone asking what is hardwood should think of species such as Okan, Azobe, Cumaru and Tali. That timber sits in class 1 to 1-2 on its own and withstands lasting ground and water contact. That makes hardwood the first pick for outdoor structures that must last for decades with little care. Think of sheet piling, dam walls, posts in the ground and decking.
Softwoods like Douglas and larch need treat or a raised base to last outdoors. Hardwood offers that protection on its own. Houthandel Jan Sok in Meppel has supplied herkomst marked hardwood since 2000. We serve private customers, sole traders and contractors from the same range (KvK 04062841, 4,8 stars from 141 plus reviews).
What it is
In practice, hardwood refers to tropical broadleaf species with high density. They have a natural hold against fungi, insects and wet. Under EN 350, the species we stock sit in class 1 or class 1-2. Class 1 means very durable, more than 25 years. So the timber works outdoors for long spells with no extra treat. That includes direct contact with ground or water (use class EN 335, GK4).
Species and class
Not all hardwood is the same, and at Houthandel Jan Sok we stock four species with their own use.
- Okan — class 1, lasting ground contact. Fine-sawn and very strong, a good pick for posts, beams and frames in the ground.
- Azobe — class 1, lasting water contact. Heavy and hard, the standard for sheet piling and dam walls in water, with a life of 30 plus years.
- Cumaru — class 1-2, 25 to 40 years. Warm golden brown (Brazilian teak), harder and richer than Douglas, liked for decking and terraces.
- Tali — class 1-2, lasting ground contact. A versatile hardwood for decking and outdoor structures.
Compare species in our pieces on Okan vs Tali for decking and the decking timber compare.
Uses
Hardwood is used where long life and load strength meet: posts for fences and pergolas, beams for load frames, planks for cladding and fencing, decking and terrace planks, and sheet piling and dam wall builds in water. For decking the life is 25 to 40 years. For Azobe sheet piling 30 plus years, even under water for good.
Plus and minus
Plus: lasts on its own with no treat, very long life (25 plus years), holds in ground and water, high frame strength.
Minus: higher price than softwood, heavier and so harder to work. Timber with no oil goes grey over time, which is only the look. The frame is not harmed. To slow the grey, oil or stain can help.
Curious how hardwood compares to a cheaper pick? Read our compare hardwood vs Douglas.
Care
Hardwood with no oil goes grey to a silver grey tone, which is only the look and does not harm the frame. To keep the first colour, pick a hardwood oil or stain and do that each year. Beyond that, a yearly clean to remove algae and dirt is enough. Hardwood can then be used for years with little care, which is one reason it is picked for sheet piling and dam walls.
Common questions
What exactly is hardwood?
Hardwood is the group name for tropical timber species such as Okan, Azobe, Cumaru and Tali. They are very dense and durable on their own. You can use them outdoors without chemical treat, even in lasting ground or water contact.
How long does hardwood last?
How long it lasts depends on the species and the use. Decking planks 25 to 40 years. Azobe sheet piling in water 30 plus years. Load frames with Okan 25 years or more. That comes from class 1 to 1-2.
Does hardwood need treatment?
No. Hardwood is durable on its own and does not need extra treat. Oil or stain is a choice and only meant to keep the colour. With no treat the timber goes grey, which is only the look.
Which hardwood species do you supply?
Houthandel Jan Sok supplies herkomst marked Okan, Azobe, Cumaru and Tali, fine-sawn, as posts, beams, planks, decking and sheet piling. See the hardwood range for sizes in stock.