NF Slate mark

Certification overview

The NF Ardoises brand is aimed at producers of natural slates. It is a comprehensive certification system including on-site audits and annual inspections of certified products and assures users (architects, project managers, control offices, roofers, consumers, etc.) that the slates covered by the certification comply with the EN 12326-1 and -2 product standards supplemented by technical specifications that reinforce the level of quality of the certification.
All the requirements to be met are described in the NF 228 certification rules.

How ?

The NF Slate certification attests to the consistency of the quality and the long-term durability of certified natural slates.

To do this, the LNE carries out an annual audit of the quality system set up by the producer as well as tests on slates taken from the site or distributors in order to verify the accuracy of the performance indicated on the products and certified.
The technical characteristics checked are as follows:

• durability
• impermeability
• size
• mechanical strength,
• frost resistance.

Why choose the NF Ardoises mark?

The affixing of the NF Slate mark gives users the certainty:
- to have slates that have proven themselves on the European market,
- the best category of slates available in terms of:

• oxidation and change of appearance,
• freeze-thaw resistance,
• behaviour with respect to acidic atmospheres,
• water absorption.

- the consistency of the quality of the certified slates.

Obtaining certification