What do FD30 and FD30S mean?

What each part of the code means

The code comes from the older British test, BS 476-22, which Approved Document B still lists. FD is a fire door. The number is how many minutes the doorset kept flames and hot gases out during the test. The S is added where a door also has to restrict smoke leakage at normal temperatures, which is why smoke seals are fitted.

The newer European route gives the same idea in different letters. E 30 is 30 minutes of integrity and Sa is the smoke leakage classification, so E 30 Sa is the European match for FD30S. A door tested either way is accepted, as long as it reaches the performance in the table.

Where each one is needed

Approved Document B sets the rating by where the door sits. A door between a flat and a space in common use, such as a shared corridor, is listed as FD30S (E 30 Sa). Other positions have their own entries in the same table, and the fire risk assessment or the building's fire strategy decides the rest. If you are not sure which rating a particular door should have, ask before you buy or replace it.

The rating belongs to the whole doorset

A leaf cannot be FD30 on its own. The rating comes from the door leaf, the frame, the seals, the hinges, the closer and the glazing, all fitted the way they were tested. Approved Document B says the test evidence has to apply to the complete installed assembly, because small differences in detail can change the result. So a good leaf hung on a poor frame, or with the wrong hinges, is not an FD30 door.

How to check what a door is

Look at the top and the hinge edge for a label, tag or plug. Many certified doors carry one. Check for intumescent strips in the leaf or frame, and for brush or fin smoke seals if the door is meant to be FD30S. Check for a self-closing device and at least three hinges. Our guide on how to identify a fire door goes through this step by step, and how to check a fire door covers the everyday checks.

No label does not always mean a failed door. Older doors that met the standard when fitted can still be adequate if they are undamaged and the gaps are in range. It does mean we cannot confirm the rating from the door alone, and a report will say so.

Sources

• Approved Document B Volume 1, Appendix C: Fire doorsets (GOV.UK)