Fire ratings: E and EI

Fire ratings for doorsets use the classifications E, EW and EI with a time in minutes: 30, 60, 90 or 120. The test standard is EN 1634-1 and LPCB runs the LPS 1056 scheme for fire doors. Pick the letter and minutes, then check the test evidence names the exact doorset construction.

• E, EW, EIIntegrity, radiation and insulation classes
• 30 to 120 minutesFire resistance periods
• EN 1634-1The fire resistance test standard
• LPS 1056The LPCB scheme for fire doors

What the fire classifications are and who publishes the standards

Fire resistance for doorsets is classified as E, EW or EI, followed by a time in minutes. E stands for integrity: the doorset’s ability to stop flames and hot gases passing through. EW adds a limit on radiated heat. EI adds insulation: a limit on temperature rise on the unexposed face. The classification therefore describes both what is being held back and for how long.

The test standard is EN 1634-1, a European standard adopted in the UK by BSI. It sets out the furnace test: how the doorset is mounted, which face is exposed to the fire, and how integrity, radiation and insulation are measured over time. The result is the classification, such as EI 60: integrity and insulation for 60 minutes.

LPS 1056 is the LPCB scheme for fire doors. Where EN 1634-1 describes the test, LPS 1056 provides third-party certification: ongoing audit of the product and its manufacture, not just a single test result. A doorset listed under LPS 1056 has been through both the furnace and the factory audit, which is why specifiers often ask for it by name.

E, EW and EI explained

The three classifications form a ladder. Each step adds a requirement on top of the last, and the table below sets out what each one demands of the doorset.

E is the base requirement: the door holds together and blocks the passage of fire and smoke for the rated period. EW matters where people or combustible materials sit close to the unexposed face, because radiated heat alone can injure or ignite. EI is the strictest of the three: the unexposed face must stay cool enough to touch, in effect, which is what escape routes and compartment walls usually demand.

The classification is always paired with a time: 30, 60, 90 or 120 minutes. “EI 60” is a complete statement; “EI” on its own is not. The time is the period the doorset held its classification in the furnace test, and it is the number the fire strategy works with when it assigns ratings to each opening.

Classification plus time, always. A fire rating is only complete when the letter and the minutes appear together, such as E 60 or EI 120. Either part on its own tells you nothing.

The fire resistance periods: 30, 60, 90 and 120 minutes

The rated period is the time the doorset maintained its classification under test conditions. It is not a guarantee that the door will survive exactly that long in a real fire; it is a standardised measure that lets fire engineers compare products and assign them to openings with known requirements.

The required period for each doorset comes from the building’s fire strategy, which in turn follows the building regulations. In England, Approved Document B gives the guidance that supports those regulations, and the fire engineer translates it into a schedule: which doors need E 30, which need EI 60, and so on. The specifier’s job is to take that schedule and buy doorsets tested to match it, not to decide the periods.

Longer is not automatically better. A 120-minute doorset is heavier, thicker and more expensive than a 30-minute one, and it may need a deeper frame and heavier ironmongery. Specifying beyond the strategy wastes money and can cause installation problems; specifying below it fails the strategy. Match the schedule.

How the fire test works

In the EN 1634-1 test, a complete doorset, leaf, frame, seals and ironmongery, is built into a furnace wall and exposed to fire on one face. The furnace follows a standard time-temperature curve, and the test runs until the doorset fails one of the criteria or the target time is reached.

Integrity is checked by watching for flames, gaps and hot gases passing through to the unexposed side. Insulation is checked by measuring temperature rise on the unexposed face against defined limits. Radiation, for the EW classification, is measured as the heat flux from the unexposed face. Each criterion is recorded separately, which is how a single test can produce an E, EW or EI result.

Because the test uses the complete doorset, every component matters: the leaf construction, the frame, the intumescent seals, the glazing and its beading, the hinges, the lock and the closer. Change any of them and the result strictly no longer applies. Fire doorsets are therefore supplied as tested assemblies, and any site modification, from a new lock to a trimmed leaf, can void the rating.

How to read a fire rating

A fire rating reads as a classification plus a time: “EI 60” means integrity and insulation for 60 minutes; “E 30” means integrity for 30 minutes. The table below shows how the common markings break down.

The rating applies to the complete doorset as tested. When you check a submittal, confirm that the leaf, frame, seals, glazing and ironmongery all match the tested assembly named on the evidence. A doorset with the right leaf in the wrong frame, or with untested ironmongery, does not carry the rating on its label.

Look for third-party evidence. A test report to EN 1634-1 proves the doorset passed once; certification under the LPS 1056 scheme proves the product is audited on an ongoing basis. Many specifications ask for the scheme listing by name, and the LPCB records can be checked against the supplier’s claim. Our fire rated steel doors are supplied with the evidence to back the rating.

How fire ratings compare with related standards

Fire is one performance among several a doorset may need. The table below shows how the fire system relates to the security standards it is often paired with.

The important pairing is fire plus security. A doorset can be tested to EN 1634-1 for fire and to LPS 1175 for forced entry, carrying both ratings with separate evidence for each. This dual certification is common on high-risk buildings where a fire door also sits on the secure line: plant rooms, risers and back-of-house doors, for example. Our fire and security doors combine a fire classification with an LPS 1175 rating in one assembly.

Do not confuse the two tests. A security rating says nothing about how long a door holds back fire, and a fire rating says nothing about how long it resists tools. Each answers its own question, and a specification that needs both must name both, with evidence for each. Our LPS 1175 guide explains the security side of the pairing.

How to specify a fire rated doorset

1. Take the period from the fire strategy. The schedule sets the classification and time for each opening; do not invent them.
2. Name the classification. State E, EW or EI as the strategy calls for, with the time in minutes.
3. Require EN 1634-1 testing. Write “tested to EN 1634-1” so the basis of the rating is explicit.
4. Specify the complete doorset. Leaf, frame, seals, glazing and ironmongery as the tested assembly.
5. Ask for third-party evidence. Require the test report and, where the strategy asks for it, certification under the LPS 1056 scheme.
6. Use a competent installer. Fire performance depends on the doorset being installed exactly as tested, with the right frame fixing and sealing.

A typical specification line reads: “Doorset tested to EN 1634-1, EI 60, complete with frame, seals and ironmongery as the tested assembly.” Where the opening also needs security, add the LPS 1175 rating on the same line and require evidence for both. Keep fire stopping around the frame in the same package: the best doorset in the world fails if the gap to the wall is left unsealed, and that sealing belongs to a competent installer.

Products rated to E and EI

ArxBridge supplies fire rated doorsets across the E and EI classifications. Fire rated steel doors cover EI 30 to EI 120 doorsets for compartmentation and escape routes. Fire rated louvre doors give E 60 and E 90 ventilation where airflow must continue through a fire-rated opening. Fire and security doors combine a fire classification with an LPS 1175 rating in one assembly, and thermally broken doors pair low U-values with a security rating for external openings. Sectors that specify fire rated doorsets include healthcare, education, residential and housing and data centres, and our security doors range covers the LPS 1175 side of dual specifications.

Frequently asked questions