Why This Matters
Getting fire ratings wrong doesn't just fail building control — it puts lives at risk. Yet the classification system confuses even experienced professionals. Here's a clear, jargon-free explanation of what E, EW, and EI actually mean, and when each is required.
The Three Fire Performance Criteria
E — Integrity Only
What it does: Prevents flames and hot gases from passing through the glass for a specified time period (30, 60, 90, or 120 minutes).
What it doesn't do: No protection against radiated heat. People close to the glass on the non-fire side could still suffer burns from heat radiating through.
Typical products: Pyroguard Integrity, Georgian wired glass, borosilicate glass (Schott PYRAN S).
EW — Integrity + Radiation Control
What it does: Prevents flames and hot gases passing through, AND limits the radiated heat on the non-fire side to below 15 kW/m² at 1 metre distance.
When it's needed: Where people may need to pass close to the glass during evacuation, or where the glass faces an escape route. This is the most commonly specified rating for commercial glazed screens and partitions.
Typical products: Pyroguard EW, Schott PYRAN Star.
EI — Integrity + Insulation
What it does: Prevents flames, hot gases, AND limits the temperature rise on the non-fire side to a maximum of 140°C average (180°C at any single point). This is the highest level of fire glass protection.
When it's needed: Where the glass forms part of a fire compartment boundary, or where combustible materials are stored close to the non-fire side. Required in many residential and healthcare applications.
Typical products: Pyroguard Protect, PYROBELite, PYROBEL, Schott PYRANOVA, Fireswiss Cool, Fireswiss Foam.
Quick Reference Table
| Rating | Flame Barrier | Radiation Control | Heat Insulation | Common Use |
|---|---|---|---|---|
| E | Yes | No | No | Internal screens away from escape routes |
| EW | Yes | Yes | No | Screens near escape routes, lobbies |
| EI | Yes | Yes | Yes | Compartment walls, healthcare, residential |
Common Mistakes We See
1. Over-specifying EI When EW Would Do
EI glass is significantly thicker, heavier, and more expensive than EW. Many commercial lobby screens and corridor partitions only require EW rating, but get specified as EI "just to be safe". This can add thousands to a project budget unnecessarily.
2. Forgetting the Frame Matters Too
The glass only achieves its fire rating when installed in a compatible, tested frame system. You can't put EI 60 glass in an untested aluminium frame and call it fire rated. The complete system — glass, frame, fixings, and seals — must be tested together.
We Supply Glass difference
We supply complete tested systems — not just glass. Our fire rated screens and doors come with compatible aluminium, steel, or timber frames, all with the correct test evidence. This means building control sign-off is straightforward, not a headache.
3. Ignoring Maximum Panel Sizes
Each fire rated glass product has maximum tested dimensions. If your design exceeds these, the glass won't have a valid fire rating — regardless of what's written on the spec. We always check your panel sizes against the test evidence before quoting.
How We Help You Get It Right
- Free specification advice — send us your drawings and we'll recommend the correct rating
- Multiple product options — we supply Pyroguard, Schott, AGC, and Fireswiss so you get the best product for the application, not just the one we happen to stock
- Complete system supply — glass, frames, fixings, and test evidence in one package
- Building control support — we provide all the documentation needed for sign-off
Related Products
Fire Rated Screens → Fire Rated Doors →Not Sure Which Rating You Need?
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