Robinia Specifications

Robinia:

  • Scientific name: Robinia pseudoacaia

  • Commercial restriction: no commercial restriction

  • Note: originates from the east of the USA. Was introduced into Europe and is grown commercially in Southeastern Europe between Hungry and Romania.

Natural Durability & Treatability:

Fungi and termite resistance refers to end-user under temperate climate. Except for special comments on sapwood, natural durability is based on mature heartwood. Sapwood must always be considered non-durable against wood degrading agents.

  • Funghi (E.N. standards): class 1-2 - very durable to durable

  • Dry wood borers: durable - risk limited to sapwood

  • Termites (E.N. standards): class D - durable

  • Treatability (E.N. standards): class 4 - resistant

  • Use class ensured by natural durability: class 4 - in ground or fresh water contact

  • Species covering the use of class 5: no

  • Note: this species is listed in the European standard EN 350-2. It is the only temperate hardwood introduced in Europe which naturally covers the use class 4.

Requirement of a Preservative Treatment:

  • Against dry wood borer attacks: does not require any preservative treatment

  • In case of risk of temporary humidification: does not require any preservative treatment

  • In case of risk of permanent humidification: does not require any preservative treatment

Log Description:

  • Diameter: from 50mm to 500mm

  • Thickness of sapwood: thin band

  • Log durability: good

Mechanical & Acoustic Properties:

  • Crushing strength: 70 MPa

  • Static bending strength: 126 MPa

  • Modulus of elasticity: 16900 MPa

(at 12% moisture content with 1 MPa = 1 N/mm2)

Fire Safety:

  • Thickness > 14 mm : M.3 (moderately inflammable)

  • Thickness < 14 mm : M.4 (easily inflammable)

  • Euroclass grading: D s2 d0

  • Notes: default grading for solid wood, according to requirements of European standard EN 14081-1 annex C. It concerns structural graded timber in vertical uses with mean density upper 0.35 and thickness upper 22 mm.

British Standard EN 350-2 Durability of wood and wood-based products — Natural durability of
solid wood:

Natural Durability:

A five class system is used for durability:

 

  1. very durable

  2. durable

  3. moderately durable

  4. slightly durable

  5. not durable

The durability given in the tables refers to heartwood only; sapwood of all wood species should be considered as belonging to durability class 5 (not durable).

The ability of wood to absorb moisture has an important effect upon its service life in out-of-ground contact, and service life in these situations depends on both its durability class and its treatability class. A wood of a given durability which has low moisture absorbing characteristics (for example treatability class 4) will, because of reduced water uptake, generally last markedly longer in out-of ground contact situations, which are subject to intermittent wetting, than a wood of the same durability rating, but which is more absorbent (for example treatability class 1).

Natural Durability to Termites:


A three class system is used:

  D - Durable

  M - Moderately Durable

  S - Susceptible

 

The durability refers to heartwood only; sapwood of all wood species is susceptible.

 

Natural Durability to Marine Borers:


A three class system is used:

  D - Durable

  M - Moderately Durable

  S - Susceptible

 

The durability refers to heartwood only; sapwood of all wood species is susceptible.

Treatability:


A four class system is used and is based on a vacuum/pressure treatment processes.

 

  1. permeable (easy to treat)

  2. moderately resistant (moderately easy to treat)

  3. resistant (difficult to treat)

  4. extremely resistant (difficult to treat)

Sapwood/Heartwood:


Typical sapwood width is given to indicate its abundance in mature trees and is categorized as follows:

 

VS - very small (< 2 cm)

S - small (2 cm to 5 cm)

M - medium (5 cm to 10 cm)

B - broad (> 10 cm)

 

The durability and the treatability of sapwood and heartwood are usually different with higher durability in the heartwood and better treatability in the sapwood.