Sep.2017. Low Lambda & NF
The NF is a certification that guarantees that the assembly of an aluminum profile with thermal bridge break has been made within certain parameters. These parameters are: Shear strength T, resistance to transverse stress Q and the durability verification of the profiles.
These basic considerations that guarantee a quality system are those that the CSTB (Center Scientifique et Technique du Bâtiment, by its acronym in French and unique body authorized to grant the NF) evaluates to certify the NF252 (specific for the assemble of profiles with thermal bridge break). The NF252 is indispensable to obtain the DTA (Document Technique d'Aplication).
The CSTB is also responsible for conducting follow-up audits as the NF is of unlimited duration, as long as the audits are complete satisfactorily.
Although NF and DTA are voluntary certifications, it is advisable to have them if you want to take a place in the French market, since it is customary to be request.
The most important differences between EN14024 and NF252, specifically for the thermal break with PA6.6 25% FG, can be summarized in the table down below.
Currently, the NF252 accepts as thermal bridge break for aluminum profiles the following materials: polyamide 6.6 with 25% glass fiber, ABS, PU or PVC.
However, Technoform Bautec has achieved that within this same classification of admitted thermal bridge break materials, the Low Lambda strips Technoform brand, are now also accepted. This means, that now, systems can be certified with this type of strips without any additional problem.
This is another advantage of our Low Lambda strips, than can be added to the virtues it already offers such as: a conductivity of 0.21 W / mK, which improves the Uw of your window, and also the opportunity to reduce the width of systems without losing thermal performance.