Properties of black locust

Black locust has been brought into Europe from North America by J. Robin, the royal chief gardener of Paris in 1601; hence they named it after him Robinia pseudoacacia.

Black locust is a “pseudoacacia”. As the Latin name suggests, it has a relationship with the acacia family (not only in our country but in numerous European countries). The acacia tree species native to Africa with a wide crown and black locust are not related botanically.

In the 19th century black locust was planted all over Europe on large territories. According to the international standard EN 350-2, black locust is the only European species that can be classified into the durability class 1-2. Because it does not require chemical treatment for outdoor applications, black locust can be considered a very environmentally friendly material. When building fences from black locust, we should keep in mind that all types of wood materials have a tendency to soak up moisture from their environment, this means that the shape of it is subject to constant change. This way designing outdoor elements requires great attention to detail, because the natural changes might affect usability and appearance. We should also consider the difficulties associated with assembling these products at home, which is considerably more difficult than any other type of wood:

  • It is almost impossible to hammer nails and drive in screws without pre-drilling the holes.
  • The tools used must be as sharp as possible and they show signs of wear pretty quickly.
  • In many cases even the power of electric tools might prove weak if we are working with black locust.

We should avoid placing the wood in concrete! It might break! A better solution would be to use metal structural elements between the wood and concrete which will allow ventilation and eliminates excess moisture; we should also avoid direct contact with the foundation because it might soak up moisture from it!

For indoor use black locust is ideal because of its high durability so there is less concern about its quick depreciation. In many cases it is more resistant and lasts longer than bathroom flooring. Furniture made of black locust is only a small percentage of the offer compared to the variety of parquetry available. These are traditionally Italian products, available in shades of hazel, and usually very pricey (only exotic and fruit tree wood is more expensive). However the quality is top notch:

  • Outdoor, in contact with the soil 25-40 years
  • Outdoor, no contact with the soil 80-100 years
  • In dry conditions and under water over 500 years.