When it comes to choosing what to put on your roof, you want to be sure it’s great quality so that it will last long and perform well.

Life is stressful enough without having to worry about the roof over your head!

But how do you really tell if slate is high quality?

A CE-mark?

Here’s the truth about CE marking…

It tells you NOTHING about the quality of the slate. Absolutely nothing.

By law, all natural slate must be CE tested, and the CE mark simply means that the slate has been tested… irrespective of whether it has actually performed well in the tests or not! There is no pass or fail criteria.

So good or bad, the slate gets a CE mark and there are some test results that you can see to decide for yourself how good quality it is.

But who knows how to interpret CE test results, let alone wants to?

You’ve got better things to do with your time than sifting through flexural strength, water absorption and carbonate content figures!

So, how can you be sure you’ve got quality slate on your hands?

It’s simple really…by looking for the NF mark.

NF Marking – The Real Deal

NF 228 is a French testing standard – you can think of it as the Michelin Star of the slate world.

Slate with an NF mark has passed all the CE tests, and more, to a very high standard.

The NF tests are carried out by an independent French lab and nobody messes with their stringent procedures.

With CE testing, the slate producer chooses slate samples and sends them to a lab in the UK for testing – but for NF testing this is just not good enough…

The independent NF testers are flown in to do the tests at the quarry. As the tests are done independently and at random, right at the source, there is no room for any monkey business, just like the Michelin process.

slate certified to nf standard

NF certificate

Each pallet of NF marked slate is traceable back to its exact source, so you can be confident that NF marked slate is the real deal and you know that the slate you specify is the slate you get.

The NF mark and barcode traceability means that you never again have to worry about being sold slate from different sources under the same brand name. You will get the consistency and quality you need every time.

Why Use a French Standard?

The slate industry in the UK looks to a French standard because the current CE certification does not have a pass/fail criteria and the NF standard is a like-for-like replacement of the arduous old British standard BS680.

France really knows its slate. 80% of the global slate production ends up there and they have a highly regulated slate industry.

We understand the value and importance of supplying you with high quality slate, and we think that the NF mark is the best way for you to really be sure that you’re getting the best quality.

Find out more about our NF certified SSQ slates here