Wood types for garden furniture
six timbers and their durability compared
Which wood is right for garden furniture comes down to a single measure: durability against wood-destroying fungi. A European standard sets it out in five classes. This page places the six timbers from our made-to-measure range, explains why the class covers heartwood only, and what that means for how long a piece lasts.
The five durability classes under EN 350
A wood durability class is not a marketing term but a measured result. The European standard EN 350 records how much mass a sample loses to wood-destroying fungi under test, and that mass loss determines the class.
| Class | Description | Mass loss under test |
|---|---|---|
| 1 | very durable | no more than 5 percent |
| 2 | durable | over 5 up to 10 percent |
| 3 | moderately durable | over 10 up to 15 percent |
| 4 | slightly durable | over 15 up to 30 percent |
| 5 | not durable | more than 30 percent |
Wood types for garden furniture in our made-to-measure range
Six timbers are available for made-to-measure garden furniture. They differ by several durability classes, and that is the most important difference between them.
| Timber | Class under EN 350 | Origin | Where it stands |
|---|---|---|---|
| Teak | 1 | South and Southeast Asia | very durable, natural oils and gum resins, the benchmark for outdoors |
| Cumaru | 1 to 2 | South America | very durable to durable, an exceptionally heavy and hard timber |
| Garapa | 1 to 2 | South America | very durable to durable, light in colour, far lighter than cumaru |
| Oak | 2 | Europe | durable, the most resistant European timber in this comparison |
| Douglas fir | 3 to 4 | Europe | moderately to slightly durable, inexpensive, wants a sheltered spot |
| Larch | 3 to 4 | Europe | moderately to slightly durable, a European classic with a limited service life |
Tropical hardwood and European timber
The six split into two groups, and the dividing line runs exactly between class 2 and class 3. That is no coincidence but a matter of how the trees grow.
Hardwood garden furniture, teak, cumaru and garapa
Slow grown, dense and rich in the extractives that fend off fungi and insects. They reach classes 1 and 2 and last outdoors without chemical preservatives. The price is correspondingly higher, and it is worth asking about origin and quality, with teak especially about the trade grade.
The European timbers, oak, Douglas fir and larch
Shorter transport distances, lower price, less durability. Oak is the strongest of them at class 2. Douglas fir and larch sit at 3 to 4, so they only cope for a limited time in ground contact or permanent damp. On a covered terrace they remain a sensible and much cheaper choice.
Siberian larch is not more durable
A widespread misconception: slower growth in a cold climate does make the timber denser, but the classification stays at 3 to 4. The name of the region on its own is not a quality mark.
What to ask about tropical timber
Country of origin, quality grade and certification. With teak, the trade grade decides whether heartwood was used at all, and durability follows from that.
What the class does not tell you
The decisive sentence in the standard: durability classes refer exclusively to heartwood. Sapwood, the outer and younger part of the trunk, is always regarded as not durable unless test data show otherwise. A piece made from a class 1 timber is therefore durable only where heartwood was actually used. With teak, that is precisely what the grades A to C decide.
Figures such as 1 to 2 or 3 to 4 are expressly provided for in the standard. If test values spread across two classes with at least 40 percent falling in each, the range is stated rather than an average. Wood is a natural material, and the site, age and origin of a tree show up in the measurement.
The class describes resistance to fungal attack and nothing else. Whether a timber is light or dark, heavy to carry, pleasant to touch and what it costs are separate questions. Cumaru and garapa share a class and are still very different woods.
Which timber for which spot
The best wood for outdoor furniture is not automatically the most durable one. Four questions get you there faster than any class number.
Covered or out in the open?
Standing free in the garden, uncovered and in ground contact, class 1 or 2 pays off: teak, cumaru, garapa or oak. On a covered terrace, Douglas fir and larch do the job well, because the permanent damp that attacks them is absent.
How long should it last?
A class 1 timber survives decades outdoors, a class 3 timber years rather than decades. If you rearrange the garden every few years, you do not need the top class.
Do you want to maintain it?
All six grey to a silver patina if left untreated, with no loss of strength. Keeping the original colour means oiling regularly and continuing to do so. Oiling once and then stopping leads to blotchy greying.
How much does weight matter?
Cumaru is among the heaviest timbers there is. For a fixed bench that is an advantage, for a piece you move around often rather less so. Garapa and the European timbers are considerably easier to shift.
Frequently Asked Questions
Sources
- EN 350:2016, Durability of wood and wood-based products. Freely accessible standard preview with the five durability classes, the mass loss thresholds and the note that the classes apply to heartwood only
- Durability classes under DIN EN 350, overview by the Bartel expert practice and the registered architect Hans-Joachim Rüpke, with the classification of individual wood species
- Choosing timber for outdoor use, same source
- Teak garden furniture at Germes
Last reviewed: 24.08.2026 · Reviewer: Germes-Team
Six timbers, one location, we find the match
Tell us where the furniture will stand, whether it is covered and how much maintenance you plan on. We will tell you which of the six makes sense there.