ASTM E119 Explained: Fire Testing, Ratings & Compliance

Under the IBC, every one-hour rating traces back to a furnace test. A lab exposes a full-scale assembly to a set fire schedule and records how long it holds. ASTM E119 is the standard behind that test.

ASTM E119 measures how long a complete assembly resists fire: a wall, floor, roof, column, or beam. It records the minutes the assembly holds back flame and heat, carries its load, or both, and that number is where the building code’s hourly fire-resistance ratings come from.

At STARC Systems, we list FireblockWall™, our reusable one-hour fire-rated temporary wall, through Intertek to ASTM E119 and ASTM E84 Class A. Intertek also inspects our manufacturing on-site.

If you’re specifying or approving a fire-rated wall for an occupied renovation, the rating on the spec sheet only helps if you can confirm the installed wall actually carries it. That starts with knowing what the test behind the rating measures.

How the ASTM E119 Test Works

ASTM requires the specimen to match real construction in materials and workmanship, and labs build it under jobsite-like conditions.

During the burn, the first applicable failure criterion determines fire endurance. A separate hose-stream requirement can also affect whether a wall earns its intended rating.

Furnace Exposure

The furnace follows the standard time-temperature curve, which climbs fast and then flattens:

• 5 minutes at 1,000°F

• 30 minutes at 1,550°F

• 1 hour at 1,700°F

• 2 hours at 1,850°F

• 4 hours at 2,000°F

Furnace controls track those targets throughout the exposure. Actual fires vary with fuel load and ventilation, so the results support comparisons under standardized conditions.

Applied Load During the Burn

Loadbearing assemblies carry their design load through the full exposure. Labs test a nonloadbearing partition, such as a temporary construction wall, unloaded, so temperature and flame limits decide its result.

Unexposed-Side Limits

For walls, the temperature-rise limits are 250°F on average and 325°F at any individual measuring point. Both values measure increases above initial temperatures.

Flame or hot gases passing through the wall in sufficient quantity to ignite cotton waste also trigger failure. A wall can remain standing while excessive heat transmission ends its fire-endurance period.

Hose Stream

Labs typically prepare a duplicate wall for the hose-stream test. It receives half the fire-endurance exposure, capped at one hour. An agreed alternative uses the original specimen after its full exposure.

ASTM E2226 specifies how the water is applied, and the stream tests whether the heated, fire-weakened wall stays intact. If water breaks through to the unexposed side, the wall fails.

Fire-Resistance Ratings and the IBC

A 1-hour fire-resistance rating means a tested assembly met every E119 limit through 60 minutes of standard exposure. A 2-hour assembly holds to the same limits through 120 minutes, and 3- and 4-hour ratings carry the same test further.

The rating is the elapsed time to the first failure, so a longer rating reflects longer proven endurance under the same standard fire.

A complete assembly carries its rating only as the tested design, so follow that design’s component requirements and permitted variations when selecting materials for the job.

The IBC splits this into two jobs. Section 703.2 names ASTM E119 or UL 263 as the test procedure that establishes a rating, and Table 601 sets the rating a project actually needs for each building element, with Table 602 and the occupancy-separation requirements covering exterior walls and separations.

The assembly a temporary wall stands in for, or breaches during the work, determines the rating it has to meet:

For an occupied hospital renovation, confirm the temporary separation requirements with the facility’s life-safety team, and coordinate any work affecting existing fire protection with the authority having jurisdiction.

Check Chapter 35 for the E119 edition your jurisdiction references, including local amendments, before preparing your submittal.

ASTM E119 vs. ASTM E84

ASTM E119 measures how long an assembly lasts in a furnace, and ASTM E84 rates how fast flame crosses a material's surface.

E84 scores a material's burn against red oak, which sets the flame spread index at 100. Class A means a flame spread index of 0 to 25 and a smoke developed index up to 450.

UL 263 and UL 1479

UL 263 is UL's version of the E119 test. The technical difference is furnace pressure, which UL 263 requires labs to record and E119 leaves optional.

If the project specifies UL 263, ask the lab to confirm compliance with that standard before testing. Request the required pressure data as part of the test plan.

UL 1479 evaluates firestop systems around pipes or cables passing through rated construction. ASTM E814 serves the same application. Both assess flame passage and heat transmission.

The F rating states how long the system resists flame passage and satisfies the hose-stream requirement. A T rating also accounts for temperature rise, using a 325°F limit above initial temperature.

UL and Intertek provide testing and certification services. Check the certification agency and applicable standard in the project specifications before selecting a listed design.

What ASTM E119 Leaves Out

ASTM E119 leaves six items outside the rating:

• Smoke and toxic gas production

• Smoke passage through the wall

• Flame spread across the surface

• Joint behavior, such as floor-to-wall connections

• Components or lengths other than those tested

• Openings such as electrical outlets, except where the tested wall included them

Check separate joint and firestop documentation wherever the wall design calls for it. Review proposed changes against the design’s permitted variations and obtain further evaluation where necessary.

Fire-Rated Temporary Walls

Rated temporary walls come as framed drywall assemblies or modular panel systems.

Drywall

Many one-hour wall designs use a layer of 5/8-inch Type X gypsum board on each side. Two-hour designs often add layers.

The specified design determines the required board arrangement and framing. Crews select studs and joint details that match its requirements.

Drywall remains an option among fire-rated wall panels for a partition that stays in one location. Repeated relocation adds demolition and rebuilding work to the schedule.

FireblockWall™

We launched FireblockWall in 2021 as the first and only reusable, modular temporary wall with a one-hour fire rating.

Crews install its panels from floor to deck for applications requiring that configuration. After teardown, the system moves to the next renovation phase and is built to be reused more than 50 times, so a multi-phase job runs on one fire-rated wall instead of rebuilding drywall at each stage.

S+B James Construction used FireblockWall inside an active California cancer treatment center during a linear accelerator replacement, supplying the one-hour separation the team needed while modifying existing corridor firewalls.

Project engineer Garrett Conrad and one carpenter installed about 45 linear feet in three days, finishing included, and Conrad estimated a conventional wall would’ve taken at least a week longer.

FireblockWall’s HCAI OPM approval also simplified the submittal. Manager Hayden Meyers estimated four weeks from first conversation to installation, against at least eight through another source.

FireblockWall is the only STARC system that carries a one-hour E119 fire-resistance rating. RealWall™ and LiteBarrier™ carry ASTM E84 Class A for surface burning, which is a different measure, so confirm a wall’s E119 rating before treating it as fire-resistant.

How to Read a Fire-Rating Listing

Work through five checks before you buy or build:

1. Find the listing. Search UL Product iQ or the Intertek directory by design number or manufacturer name.

2. Check the rating and the burn face. Wall ratings apply when either face burns, except where the design says otherwise.

3. Read the load note. A load-bearing rating covers nonload-bearing use, and any restriction on the design stays in force.

4. Read the component notes. Follow the stated conditions for optional items and any permitted substitutions. Check dimensional limits before ordering materials.

5. Check door protection. For swinging fire doors, review the NFPA 252 or UL 10C documentation. Use the applicable IBC opening-protection table to confirm the required rating for the wall’s classification.

Matching ASTM E119 to Your Project

The furnace test sets the hourly rating, the code says which rating a given separation needs, and the listing proves the installed assembly matches both.

A fire-rated temporary wall belongs in that chain whenever a renovation has to hold a rated separation while the permanent construction stays open.

Once your ASTM E119 documentation matches the project requirements, request a quote for the specified temporary wall configuration.

Frequently Asked Questions

What is a one-hour fire-resistance rating?

A one-hour fire-resistance rating means an assembly satisfies the applicable test criteria for 60 minutes under standard fire exposure. The rating describes performance under controlled conditions.

Is ASTM E84 Class A a fire-resistance rating?

ASTM E84 Class A is a surface-burning classification. Class A requires a flame spread index of 0–25 and a smoke-developed index of 0–450. Separate testing establishes hourly fire resistance.

What is ASTM E84 equivalent to?

ASTM E84 is equivalent to UL 723 for evaluating surface-burning characteristics. Building codes accept either test for classifying interior finishes. Both report flame spread and smoke-developed indexes.

How can you identify fire-resistant drywall?

You can identify fire-resistant drywall through manufacturer markings and product documentation, including Type X designations. Match the board to the specified wall design to verify the assembly’s hourly rating.

Which ASTM E119 edition is current?

The current ASTM E119 edition is E119-26. ASTM lists it as active, with a January 29, 2026 update. Confirm which edition your jurisdiction references before preparing your submittal.