A new way of conceiving the African wood
Posted on August 25, 2011The approval of the D.L. 39/2009, and the entry into force of the Ministerial Decree 14.01.2008 resulted in the Enterprise Sector of the Construction of the certification requirement of products.
The Construction Products Directive sets out key requisites. The conformity of a product with these requirements shall be attested by the CE marking.
Few tropical hardwoods have already been recognized using this brand, and many are imported into Europe without any structural analysis.
Vasto Legno therefore wanted to designate one of his main, distinctive species, the Sapele, in the aim to lead it into the UNI-EN 1912 (Structural timber – Strength classes – Assignment of visual categories and species).
SAPELE: “ENGINEERED” WOOD
Vasto Legno accordingly committed to FCBA, one of the most esteemed European Organization, the task to delineate the distinctive principles of Sapele, coming from the Congo Basin.
The mechanical characterization has been developed according to strict regulatory documents, in order to get to the CE labeling.
The final results of the marking process has been very satisfactory, thus leading Sapele, coming from the Congo Basin, to be included in class D40, where also belong the Iroko and Oak.
Table 1: Strength class assigned to Sapele from FCBA.
Here below the characteristic values of strength class D40.
Table 2: Characteristic values of strength class D40.
DURABILITY
The European regulatory reference document to define the durability of a species is the UNI-EN 350-2. This rule governs 5 natural durability classes, ranging from 1 (very durable) to 5 (not durable).
Below are listed, for comparison, the values of some characteristic species.
Table 3: Values of natural durability.
DECKING – Class of use 3b
In the analysis of durability, it is also useful to analyze the fungal and insect durability respect to the class of employment in which the species will be used. Specifically, for the decking, the class of use is considered to 3b. The use is outdoors in situations where the wood is not in direct contact with the ground and it is subjected to significant periods of frequent wetting. The wood drying is complete before the next period of humidification. The wood is exposed to direct contact to the elements in a condition that allows the rapid draining of water.
One more time, for comparison, here there are some of the most used tropical species in decking and their fungal and insect durability characteristics.
Table 4: Natural durability (no sap) of tropical species exposed to insects or fungi attacks.
Here below the descriptively values of durability fungal are shown:
- L3: more than 100 years longevity;
- L2: longevity between 50 and 100 years in the use originally intended ;
- L1: longevity between 10 and 50 years in the use originally intended ;
- N: uncertain longevity and, in any case, less than 10 years: not recommended for external use.
SUSTAINABILITY
Vasto Legno has always been careful to ecology of forest stands, through sustainable forest management and selviculture. The timber exploitation is consonant with the productivity of forests, with the goal of keeping the forests intact for future generations.
Following this policy and of the constant commitment in the settlement of their territories, all the forests, from which the timbers come, are certified OLB.
