FD30 vs EI30 vs EI60: which fire rating does your glass partition actually need?

Quick answer: FD30 is a British fire door rating. It describes a door that holds back fire for 30 minutes in a BS 476-22 test. A fixed glass partition is classified differently, under the European system (BS EN 13501-2), as E, EW or EI plus a number of minutes. EI30 and EI60 mean the glazing keeps both its integrity and its insulation for 30 or 60 minutes. If a spec asks for an "FD30 glass partition", it is mixing the two systems, and it's worth checking what the fire strategy really needs.

Two rating systems, one building

The UK uses two ways to describe fire resistance, and both appear on drawings.

The British route (BS 476). Doors tested to BS 476-22 get an FD rating: FD30, FD60 and so on, with an "S" added (FD30S) when the door also has smoke seals. The number is how many minutes the door kept its integrity in the test.

The European route (BS EN 13501-2). Elements tested to European standards (BS EN 1634-1 for doors, BS EN 1364-1 for non-loadbearing walls and glazed partitions) get letters for each thing they achieved, plus the minutes:

So EI30 means integrity and insulation for 30 minutes. EI60 means the same for 60 minutes. E30 means integrity only.

Where FD30 and EI30 get confused

The mix-up usually happens when a glazed screen contains a door. The door has its own rating, often FD30S. The glass around it is a separate element with its own classification. When a spec just says "FD30 partition", nobody can tell from that line whether:

• only the door needs FD30 and the side screens need nothing,
• the whole screen needs to hold 30 minutes of integrity (E30), or
• the screen needs integrity and insulation (EI30).

Those three answers lead to very different glass, frames and prices.

The British route is also on its way out. From 2 September 2029, the amended Approved Document B for England no longer names BS 476-22 testing for fire doorsets. It points to European classification under BS EN 13501-2 (tested to BS EN 1634-1) instead. Specifying in European classes now saves a re-spec later.

Why E versus EI matters for your budget

Integrity-only fire glass (E) stops flame and smoke passing through, but heat can still radiate through the pane. Insulating fire glass (EI) is a laminated product with layers that turn opaque and foam up in a fire, which blocks the heat as well. It's thicker, heavier and costs noticeably more.

Specifying EI where E would do adds cost for nothing. Specifying E where the fire strategy needs EI can mean a failed inspection and glass that has to come out. Neither is a mistake you want to find at sign-off.

EI30 or EI60?

The minutes come from the building's fire strategy, not from the glazing supplier. For offices, Approved Document B (Volume 2, Table B2) sets a minimum of 30 minutes where the top floor is up to 5m above ground. Without sprinklers, that rises to 60 minutes up to 18m and 90 minutes up to 30m. With sprinklers, 30 minutes applies up to 18m and 60 minutes up to 30m. Your fire engineer or building control officer confirms which applies to each wall.

What to check before you order fire-rated glazing

1. Get the fire strategy drawing. It should mark each rated wall and door with a classification and minutes.
2. Read the letters, not just the number. E30, EW30 and EI30 are three different products.
3. Rate the door and the screen separately. A fire door in a glazed screen needs evidence for both, ideally tested together as one assembly.
4. Ask for the classification report. A test certificate for the exact system, glass type and maximum pane size you are buying.
5. Install it as tested. Fire ratings only hold when the glass, frame, seals and fixings match the tested configuration.

How Weldholm handles fire-rated glazing

Our WH-78EI system is classified EI30 and EI60 and reads as near-frameless glass: panes are joined with a 4mm joint filled with intumescent firestop material and non-flammable silicone, in black, grey or white. Modules go up to 1.5m wide at 3.6m high, or 1.8m wide at 3.0m high, and the system is CE-marked.

Not sure what your drawings are asking for? Send us the fire strategy and floor plan, and we'll confirm which rated system fits each run, priced the same working day.

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