What is roundwood?
The Wood Guide · Calculating with wood
Building timberRoundwood
Straight from the forest, stripped of its bark but otherwise in its natural shape. Used in garden structures, play equipment and rustic building.
- Only debarked
- All diameters
- Softwood and hardwood
Roundwood
Straight from the forest, stripped of its bark but otherwise in its natural shape. Used in garden structures, play equipment and rustic building.
Click a chapter or use the arrows.
Roundwood in brief
Unprocessed or minimally processed logs that come straight from the forest. Usually only debarked, and otherwise not sawn or planed.
By keeping the natural round shape, something else is kept too: the continuous fibre. In a sawn beam the fibres at the sides are cut through; in roundwood they run uninterrupted from bottom to top. That makes a round post stronger than a square beam of the same cross-section from the same tree.
On top of that, the outer growth rings — the strongest, densest part of the trunk — remain intact. Sawing always means removing that outer layer.
Roundwood has no sharp edges, is strong even at small diameters, and has a natural look that suits a green setting. That is why play equipment, climbing frames and fencing in parks are almost always made from it.
- Processing
- only debarked, sometimes peeled
- Shape
- the natural round shape of the trunk
- Sizes
- all diameters and lengths
- Species
- softwood and hardwood: pine, oak, Douglas fir
- Strength
- continuous fibre, outer rings intact
- Use
- garden, play equipment, rustic building
To be fair: roundwood is not dimensionally consistent and not uniform. Every post has a different diameter, a taper and its own curve. So everything you build with it needs fitting work on site — that is the charm, and it takes time.
How to recognise roundwood
Minimal processing
Usually only stripped of its bark; the natural round shape of the trunk is kept.
Wide range of sizes
Available in all kinds of diameters and lengths, depending on the original tree and the intended use.
Different wood species
Both softwood and hardwood — pine, oak and Douglas fir are the most common.
Tapered
Every trunk gets thinner towards the top. That is not a flaw but a given you take into account when designing.
What roundwood is used for
| Use | Why roundwood | What to look for |
|---|---|---|
| Posts and fencing | Strong even at small diameters | Ground contact requires pressure-treated wood or class 1–2 |
| Play equipment | No sharp edges, natural look | Peeled smooth and splinter-free |
| Pergolas and arbours | Rustic look, continuous fibre | Above ground, class 3 is sufficient |
| Bank revetment and riverbanks | Resistant to permanent moisture | Oak, robinia or pressure-treated softwood |
| Rustic furniture | Character | Let it dry completely first, otherwise it will crack later |
| Log cabin building | Traditional technique | Allow for settlement of the walls |
A roundwood post almost always develops one deep lengthwise crack as it dries. That is because the outside shrinks faster than the core, and the tension is released in one place. It is normal and hardly affects the load-bearing capacity — but it is the reason roundwood is rarely used in visible interior work.
Frequently asked questions about roundwood
Is roundwood stronger than sawn timber?
At the same cross-section it usually is, because the fibres run continuously instead of being cut through, and the strong outer growth rings remain intact.
Why does roundwood crack lengthwise?
The outside dries and shrinks faster than the core; that tension is released in one deep lengthwise crack. Normal, and it hardly affects the load-bearing capacity.
Which roundwood can go in the ground?
Pressure-treated softwood in use class 4, or a naturally durable species such as robinia, oak or sweet chestnut.
What is the difference from pole timber?
Pole timber is roundwood that has been graded by size and diameter for post applications, often machined to an even round cross-section and pointed.
Roundwood in perspective
The trunk as it grew — stronger than what you saw out of it.
Have a question about your project? Just ask — we're happy to help.
Photos via Wikimedia Commons: Gschnitz, Tyrol — Kritzolina, CC BY-SA 4.0 · Deggendorf, Bavaria — APneunzehn74, CC0