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A fire test report is the evidence behind a fire rating. Without a valid report, a "60-minute wall" is just a claim. But reading a fire test report properly is not obvious — the numbers on the front page are only the headline, and the details inside determine whether your installation actually achieves the rating. This guide explains what to look for, what each section means, and the fine print that catches people out.

What is a fire test report?

A fire test report is a document produced by an accredited testing laboratory after conducting a fire test to a recognised standard. It describes:

• The construction that was tested (boards, insulation, studs, fixings)
• The test standard and procedure
• The test results (integrity, insulation, loadbearing capacity)
• The performance achieved (in minutes)
• Any specific conditions or limitations on the rating

Fire test reports are legally important. Building Control, fire engineers, and insurers all rely on them. If a wall fails to perform in a fire and the installation doesn't match a valid test report, the consequences can be severe — for the contractor, the designer, and the building owner.

The front page — what the headline tells you

Every fire test report has a front page with the key details:

• Test report number — the unique reference for the test (e.g. EUI-24-000388)
• Test standard — which standard the test was conducted to (BS EN 1364-1, BS 476 Part 22, etc)
• Test date — when the test was carried out
• Client / sponsor — who commissioned the test
• Test specimen description — a one-line summary of what was tested
• Result — the fire rating achieved (e.g. 60 minutes, integrity and insulation maintained)
• Classification report number — the separate document that classifies the result to a standard (e.g. BS EN 13501-2)

The headline result is what most people look at. But the headline result is only valid for the specimen described — not for any variation the contractor might prefer on site.

The build-up details — what was actually tested

The most important part of the report is the detailed description of the test specimen. This typically includes:

Boards

• Manufacturer and product name (e.g. BG Fireline, Siniat Fire Board)
• Thickness (12.5mm, 15mm, 19mm)
• Number of layers (1, 2, 3)
• Orientation (horizontal or vertical)
• Fixing method (screw type, length, spacing, edge distance)
• Joint treatment (taped, filled, staggered)

Insulation

• Manufacturer and product name (e.g. Rockwool RWA45, APR 1200 roll)
• Thickness (50mm, 60mm, 100mm)
• Density (kg/m³)
• Fixing method (friction fit, stapled, wire-supported)

Studs and tracks

• Profile (C stud, I stud)
• Width (70mm, 90mm, 100mm, 146mm etc)
• Gauge (1.2mm, 1.5mm, 2.0mm)
• Centres (600mm, 400mm)
• Manufacturer and product code

Fixings

• Screw type and size
• Screw spacing (typically 300mm or 250mm for fire-rated systems)
• Edge distance from board edges
• Track fixings (anchors to concrete, screws to steel)

Field of application

Some fire test reports include a "field of application" or "extended application" document. This is a formal statement by the testing laboratory that describes how far the test result can be extended to variations:

• Can a tested 70mm stud be substituted with 90mm?
• Can a tested 600mm stud centre be substituted with 400mm?
• Can a tested 2 × 12.5mm board build-up be substituted with 2 × 15mm?
• Can a tested 60mm insulation be substituted with 100mm of the same type?

The field of application document is what allows a manufacturer to publish a "system range" — several build-ups covered by the same test. If a variation is not covered by the field of application, it is not covered by the test, and a separate test would be required.

If a report doesn't include a field of application, you must assume that only the exact tested build-up is covered.

The test standard

UK fire tests use one of two standards:

• BS EN 1364-1 — European standard for non-loadbearing partitions. Current preferred standard for new systems.
• BS 476 Part 22 — older British standard, still valid for older tested systems.
• BS EN 1365-1 — European standard for loadbearing walls (includes a load, so it tests structural performance under fire).
• BS 476 Part 21 — older British standard for loadbearing walls.

Both BS EN and BS 476 tests are recognised by Building Control. The standards differ in some procedural details but produce comparable results. If a report cites BS 476 Part 22 but the project requires BS EN 1364-1 (some specifications demand the newer standard), the older report may not be acceptable.

Exposed vs unexposed side

Fire tests are directional. The test specifies which side of the wall was exposed to the fire (the "exposed" side) and which side was the "unexposed" side. In some cases, the wall is tested from both directions — but in many tests, only one direction is tested.

This matters because:

• A wall may perform differently depending on which side is exposed — the build-up of boards on the fire side is critical
• If a wall has asymmetric boards (e.g. fire board on one side, sheathing on the other), the tested direction must match the installation
• Some walls are tested in both directions and can be used either way; others aren't

Check the test report to confirm which direction(s) were tested. If your wall will have fire on the sheathing side (e.g. an external wall with fire inside), you need a test that was carried out in that direction.

What the report doesn't tell you

Fire test reports have limitations. They don't tell you:

Acoustic performance

Fire tests measure fire performance only. Acoustic performance is measured in separate tests to separate standards (BS EN ISO 10140 or BS EN ISO 717-1). A wall can be excellent for fire and mediocre for acoustics, or vice versa. Don't assume a fire rating implies an acoustic rating.

Structural performance (unless it's a loadbearing test)

Non-loadbearing fire tests (BS EN 1364-1) don't test the wall's structural performance. The wall may pass the fire test but not be suitable for loadbearing or high wind loading. For those applications, a separate structural design is required.

Real-world performance

Fire tests are carried out in controlled laboratory conditions, on a specific specimen, by qualified technicians. Real-world installation may differ due to site conditions, workmanship, or material variations. The test result is the best-case performance under ideal conditions.

Durability of the fire performance

Fire tests don't assess how the performance changes over time. If a wall is exposed to moisture, movement, or damage, the fire performance may degrade. Regular inspection and maintenance are still required.

Substitutions — when you can deviate

The most common cause of invalid fire ratings on site is substitution. Someone decides to:

• Use a different board brand because it's cheaper
• Skip the insulation because "it's only 60 minutes"
• Use a wider stud because it's what's in stock
• Use 600mm screw centres instead of 300mm because it's faster

Each of these may seem minor, but each invalidates the fire rating unless the field of application document explicitly permits it.

The rule is simple: if it's not in the report or the field of application, it's not covered. Ask the manufacturer to confirm in writing that a substitution is acceptable before making it.

Summary

A fire test report is a detailed document that describes exactly what was tested. The headline result (60 minutes, 90 minutes, etc) is only valid for the tested specimen. To apply the rating to your project, you must match the tested build-up exactly, or confirm that your variation is covered by the field of application.

Key things to check:

• Test standard (BS EN 1364-1 or BS 476 Part 22)
• Exact board type, thickness, layers, and manufacturer
• Exact insulation type, thickness, and density
• Exact stud profile, width, gauge, and centres
• Exact fixing method and spacing
• Tested direction (exposed side)
• Field of application (for any variation)

When in doubt, ask the manufacturer. Getting it wrong on site is expensive and potentially dangerous.