Certification in the wood preservation sector

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Treated timber for deckings

Floor covering structures used outdoors and simple to install.

They are composed of timber strips attached to floor battens and intended for use as pathways (edges of swimming pools, etc.) or parking areas (outdoor fairs, etc.)

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The performance of decking is ensured by the use of a certified treatment
product and the implementation of a controlled process.
Strips and battens that have been according to CTB-B+ specifications are reliable in terms of use and expected durability. They are suitable for the uses described in the DTU 51.4 [unified technical document] that specifies, for example:
• the use class is 4 (or 3.2 for
particular conditions)
• the expected durability is less
than 10 years
• the use of a reliable and
approved product, guaranteed
by implementation

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CTB-B+ treated wood ensures the service life of the decking in service. To ensure its durability, the
installation rules for these products, laid down in DTU 51.4 should be observed, and in particular :
• ensure the timber is effectively ventilated
• prioritise drainage to prevent retentions and water traps
• prohibit any machining after treatment. However, for cuts and holes, the exposed surfaces should be treated with a suitable
product in order to help rebuild the initial level of protection
• respect the characteristics of the strips defined in NFB 54.040
• take account of the humidity of the wood when it is installed

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CTB-B+ treated strips do not
require the application of any
additional products to ensure
Its aesthetic appearance is maintained
by cleaning using a brush
and/or water jet (high pressure
prohibited) or by the application of
decorating products.

Universal use classes, specifications of different treatments :

Before choosing the timber species, please refer to the use class. Identical in every country, the uses classes define the situation of the timber in a particular structure. They do not, however, attest to its suitability for use. For the same use class, the treatment requirements may vary from country to country. Each species has its own characteristics in terms of natural durability (before treatment) and impregnability (capacity to retain the product). The allocation of a species to a use class determines how the timber should be treated. Its effectiveness depends on the selection of the timber, the quality and quantity of the product used and how the process is managed and controlled.
tableau des classes d'emploi du bois 4
Schéma des classes d'emploi du bois classe 4 pour les terrases

Fiche technique pour bien comprendre les classes d'emploi des bois



To help professionals make the right choices, holders of the CTB-B+ Mark publish a brochure entitled
«Fully understanding the classes of use ».

Download Fully understanding the classes of use