100% Hardwood (FSC seal of approval)

High-standard seat rests require high-standard wood with high density. Hardwood is therefore especially suitable for seat rests – because of its stability, processing properties, availability, natural appearance and above all because of its isolating effect. We only use 100% high standard hardwood from certified distributors*) from controlled forest management.

For high-standard building projects the hardwoods of tropical origin have nearly replaced local wood sorts such as larch and pine. The reason for this development is mainly the lower maintenance effort and the longer durableness.

Compared to other wood hardwood is more resistant against environmental damage like UV radiation and dampness. If installed correctly the wood is resistant against pest infestation and insensitive to mould.

Oiling helps against wood turning grey

The greying of the wood surface is a natural phenomenon: photochemical, physical and biological processes take place under sunlight. The lignin which is like a glue for the cell compound is washed out of the wood.

Without treatment every hardwood turns grey within a few months and takes on a typically greyish look. This process can be slowed down by oiling. But oiling has no influence on the life period of the hardwood, which can be more than 30 years in a temperate climate, depending on the type of wood.

Hartholzbank mit silbergrauer Patina, die sich bereits nach wenigen Monaten einstellt

A bench made from hardwood with its silver-grey patina, which evolves after a few months.


Lumber, the pre-product for the fabrication of seat rests, is practically available in all sizes. For practical and technical reasons two standard sizes have proved advantageous, which we therefore have on stock: 65 x 65 mm² (0.21 x 0.21 ft²) and 130 x 65 mm² (0.43 x 0.21 ft²). Of course other sizes are still available.

Hartholz Sitzauflage mit Querschnitt 65 x 65 mm²

Seat Rest, cross section 65 x 65 mm² (0.21 x 0.21 ft²)

Hartholz Sitzauflage mit Querschnitt 130 x 65 mm²

Seat Rest, cross section 130 x 65 mm² (0.43 x 0.21 ft²)

Which tree and which wood is meant by "100% hardwood"?

100% hardwood is a collective term for all wood which is best quality, extremely hard and particularly weather-proof. This wood normally comes from tropical origin. The hardwood we use and deliver is distinctive regarding the following criteria:

  • particularly weather-proof
  • High wood density and thus high strength and wear stability
  • little danger of crack initiation (we only work with kiln-dried wood)
  • very few embeddings

Hardwood is formally defined as a collective term for all sorts of wood with a gross density of 0.55 g/cm³ (based on dried condition). Well-known representatives for European hardwood are e.g. beech, oak and ash trees. The actual type of tree chosen depends on the availability of the raw material. At the moment we often use a sort of wood called “Meranti” (other names: “Seraya” or “Balau”). In order to be deliverable we always have a certain amount of raw material on stock.

Even 100% hardwood of tropical origin is not perfect

Wood is and stays a natural product. The irregularities regarding texture, color and structure are what makes wood what it is: a natural and heartwarming material.

The label 100% hardwood of tropical origin masks the best and most suitable wood sorts for seat rests that are available. But this material is not perfect either. There can still be:

  • embeddings due to branches
  • differences in color
  • cracks
  • Residual resin
  • worm holes

As modern street furniture is usually not designed with a look of matured timber, worm holes are unwanted although they can still turn up:

Hartholz mit tropischer Herkunft -

Example: worm holes in 100% hardwood of tropical origin

Ist Eiche als Werkstoff für Sitzauflagen geeignet?

Many architects and constructors want to use wood of European origin. Often they ask for German oak. We advise against doing so for the following reasons:

  • Danger of long and deep cracks which may even make the seat rest unusable
  • Due to the high ratio of tannic acid the oak is extremely sensitive towards the contact with iron particles. The surface can partly turn black-grey The surface may then turn black-grey
  • The oak boards loose color during the first years which leads to color stains on the ground and the near surroundings

Tender Templates

“100% hardwood (certificate), quality category 1, few embeddings due to branches, kiln-dried with residual moisture below 20%. Surface area planed and sanded on all sides, all edges chamfered 3 x 45°. Surface sliqutly oiled.”


Anwenderinformation zu Sitzauflagen


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