EI 90 Fire Rating
EI 90 fire rating (EN 13501-2): what it means & when to specify it
EI90 fire rating
EI 90 fire rating is a 90-minute fire-resistance classification where a construction maintains integrity (E) and insulation (I) for an hour and a half. Integrity prevents flames/smoke passing through; insulation limits the temperature rise on the unexposed face, protecting people and adjacent materials for the full duration. Compared with EI 60, EI 90 imposes tighter limits on glass, profiles, seals, and junctions – and demands meticulous installation control.
At a glance
- What it does: Stops flames/smoke and limits surface temperature rise for 90 minutes.
- What it doesn’t do: Not a load bearing rating (that’s R).
- Typical use: Protected routes in complex buildings, compartment boundaries to higher-risk areas, and locations with close occupant proximity or sensitive combustibles.
- Standards: Classified to EN 13501-2; typically tested to EN 1634-1 (doorsets) or EN 1364-1 (non-loadbearing walls), with general methods from EN 1363-1/-2.
How EI 90 is tested
- Furnace exposure: Specimen follows the standard time–temperature curve.
- Integrity (E): No sustained flaming, no through-gaps beyond limits, no ignition of the cotton pad.
- Insulation (I): Average safe-side temperature rise ≤ 140 °C above ambient; maximum at any point ≤ 180 °C for 90 minutes.
- Resulting class: If both criteria are met for 90 minutes, the element is EI 90.
- Evidence to hold: A classification report and supporting test report(s) matching your exact configuration.
Note: EI’s insulation criterion keeps safe-side surfaces cooler, which also reduces radiant heat to safer levels for nearby occupants and finishes.
EI vs EW vs E - what’s the difference? | |||
|---|---|---|---|
| Property / Class | E (Integrity) | EW (Integrity + Radiation) | EI (Integrity + Insulation) |
| Stops flames/smoke passing |  | | |
| Limits radiant heat near the element |  | (radiation control) | (via low surface temperature) |
| Limits temperature rise on unexposed face | | | (ΔTavg ≤ 140 °C; ΔTmax ≤ 180 °C) |
| Typical glazing make-up | Integrity fire glass | Radiation-control glass | Insulating fire glass (multi-laminate/intumescent) |
| Typical use cases | Low-proximity zones | Radiation control where EI not required | Close-proximity routes, protected spaces, sensitive areas |
Where EI 90 is typically required or preferred
- Protected lobbies, corridors, refuges and stair enclosures in larger/complex buildings.
- Compartment boundaries to higher-risk rooms (plant, high-load stores, commercial kitchens) abutting circulation.
- Healthcare, education, residential routes where vulnerable occupants or combustibles may be near the glazing for extended periods.
- Boundary conditions where the fire strategy requires insulation for 90 minutes to protect adjacent property or escape routes.
- Always confirm with the project fire strategy, local regulations, and the scope of your classification report.
Selecting an aluminium system for EI 90
1) Use a tested, documented assembly
Follow the exact combination of profiles/reinforcements, glazing, beads, seals, intumescent components, fixings, substrates and hardware stated in the classification report.
2) Glass type
Specify EI-rated insulating fire glass compatible with the system. These are typically multi-laminate/intumescent constructions with defined thickness, edge cover and weight; do not substitute EW or E glass.
3) Sizes & limits
Respect pane/leaf maximums, aspect ratios, visible edge cover, mullion/transom centres and profile spans. Oversizing requires formal EXAP/assessment.
4) Glazing details
- Maintain specified setting blocks/packers, intumescent liners/foams, and sealants.
- Replicate glazing bead geometry and fixing patterns exactly, including screw type/spacing.
5) Hardware & accessories
Only use listed hinges, locks, closers, panic hardware, drop seals and any electromagnetic hold-open devices referenced in evidence. For 90 minutes, verify closer power, bearing capacity and thermal protection of ironmongery.
6) Interfaces & substrates
Install into the tested substrate (e.g., concrete, lined stud). Match perimeter firestopping density/depth and record movement joints and deflection criteria.
7) Identification & maintenance
Apply ID labels, include DoP, installation and O&M manuals, and plan inspections (glass edges, seals, ironmongery). Longer-duration EI assemblies benefit from documented maintenance intervals.
Aluminium fire-rated windows, doors & glass partitions (EI 90)
EI 90 fire rating is achievable in aluminium systems when the tested build-up is followed precisely.
Fire-rated windows (EI90)
Scope: Usually fixed lights; openable EI-rated windows are uncommon and must be explicitly tested with the exact operating hardware and seals.
Glazing: Use the tested EI glass (type/thickness) and maintain edge cover and intumescent liners as specified.
Locations: Internal partitions to protected routes; external/boundary applications where the strategy requires 90-minute insulation.
Spec tips: Confirm pane maximums, permitted mullion/transom types, head/sole details; coordinate ventilation via AOVs or separate systems.
Fire-rated doors (EI90)
Leaf types: Single/double leaves, with/without overpanels/side-lights – each configuration must be covered by evidence.
Hardware: Only listed hinges, locks, closers, panic devices, drop seals. If hold-open is needed, use an automatic release linked to the fire alarm.
Additional performance: Smoke control (Sa/Sm) is separate to EI; include if required.
Spec tips: Check clearances, closer power, glazing bead type, ironmongery packers, and any kick/guard plates.
Fire Rated Glass Partitions / Screens (EI90)
Layout: Keep to tested post spacing, deflection limits, and head-of-wall junctions. Unframed/butt-jointed glass is typically not permitted for EI unless specifically tested.
Interfaces: Use only approved fire stopping and tested substrates; document any movement joints.
People proximity: EI is preferred where occupants or combustibles may be close to the safe face for prolonged periods.
Spec tips: For door-integrated screens or full-height runs, ensure the combined assembly (door + side-light + overpanel) is within scope.
Build exactly to the documented configuration. If your intended size, hardware, glass or junction isn’t covered, obtain EXAP/assessment before proceeding.
Compliance & documentation (what to keep on file)
- EN 13501-2 Classification report stating EI 90 and permitted configurations.
- EN 1634-1 / EN 1364-1 test reports matching your build-up.
- Declaration of Performance (DoP) and relevant CE/UKCA marking.
- Installation guide and maintenance schedule.
- Any EXAP/Assessment extending field of application.
- Our Compliance Pack example
Model specification clause
Fire-rated aluminium doorset/screen – EI 90
Provide and install a factory-fabricated aluminium glazed doorset/screen classified to EN 13501-2: EI 90, tested to EN 1634-1/EN 1364-1 as applicable.
Construction, glazing, edge cover, seals, intumescent components, hardware and fixings shall match the tested/classified configuration.
Maximum sizes and aspect ratios shall not exceed those in the classification/assessment.
Install per the manufacturer’s instructions with approved perimeter firestopping.
Provide DoP, classification report, installation and maintenance manuals at handover.
EI 90 fire rating FAQs
What does EI 90 fire rating mean?
The element maintains integrity and insulation for 90 minutes: no through-flames, and the safe-side temperature rise is limited (ΔTavg ≤ 140 °C; ΔTmax ≤ 180 °C).
When should I choose EI 90 over EW 90?
Choose EI 90 where the fire strategy requires 90 minutes of insulation – e.g., higher-risk compartments, complex buildings, or where people/combustibles are near the glazing for extended periods.
Does EI 90 fire rating include smoke control?
No. Smoke control (Sa/Sm) is a separate classification and must be specified and evidenced independently.
Can I mix EI doors with EW screens in one elevation?
Only if the combined assembly (door + screen + overpanel) is covered by evidence. Otherwise keep the elevation to EI or obtain an assessment.
What glass types achieve EI 90 fire rating?
Insulating fire glass (multi-laminate/intumescent) matched to the aluminium system, with specific thickness, weight and edge cover per the report.
Can I oversize panes or change ironmongery?
Not without formal EXAP/assessment. Stick to tested sizes, hardware and construction to retain the EI 90 classification.
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