Technical Standard

ASTM E84 Fire Ratings: Class A, B, C for Wallcovering

ASTM E84 measures how fast flame travels across a wallcovering and how much smoke it makes. Class A (flame spread 0–25) is what most commercial and hospitality interiors require, and paper-backed natural wallcovering can reach it on gypsum board with a fire-retardant backing.

By: Yuxing Qin, Material Specialist7 min read
ASTM E84 Steiner tunnel test chart showing Class A, B and C flame spread ranges beside natural wallcovering samples
Quick answer: ASTM E84 (the Steiner Tunnel test, also published as UL 723) rates a wallcovering by Flame Spread Index and Smoke Developed Index. Class A is FSI 0–25, Class B 26–75, Class C 76–200, each with SDI 0–450. Most US commercial and hospitality interiors require Class A. Paper-backed grasscloth and sisal can reach Class A on gypsum board with a fire-retardant backing; the buyer or brand commissions the test for their market.

Key Takeaways

  • Two numbers, one test: ASTM E84 / UL 723 reports Flame Spread Index and Smoke Developed Index from a 10-minute, 24-foot tunnel burn.
  • Class A = FSI 0–25, Class B = 26–75, Class C = 76–200; SDI must be 0–450 for every class.
  • The rating is system-dependent: the report is valid for the tested wallcovering + adhesive + substrate, normally Type X gypsum board.
  • NFPA 255 is withdrawn (2011); specifications should cite ASTM E84 or UL 723.
  • "Type II" is not a fire class: it is a vinyl weight grade from CCC-W-408 / ASTM F793 (minimum 13 oz/sq yd, 20 oz per 54-inch linear yard).
  • The code decides: IBC Chapter 8 sets the class by occupancy and location; NFPA 286 is the room-corner alternative some AHJs require for textile wall coverings.

What Is ASTM E84 and How Does It Work?

ASTM E84 (also known as the Steiner Tunnel Test or UL 723) is the standard test method for surface burning characteristics of building materials. A 24-foot sample is mounted in a tunnel and exposed to a controlled flame for 10 minutes. Two measurements are taken:

  • Flame Spread Index (FSI): How quickly and far the flame travels across the material surface
  • Smoke Developed Index (SDI): How much smoke the material produces during combustion

What Do the Fire Classes Mean?

ClassFlame Spread IndexSmoke Developed IndexTypical Requirement
Class A0 – 250 – 450Hospitals, schools, hotels, high-rise, assembly
Class B26 – 750 – 450Some commercial, corridors, lobbies
Class C76 – 2000 – 450Residential, some low-occupancy commercial

Key point: Most commercial projects require Class A. Always verify with your local Authority Having Jurisdiction (AHJ) — code requirements vary by occupancy type, building height and location within the building.

How Does Natural Wallcovering Perform?

MaterialTypical Rating (on gypsum board)Notes
Grasscloth (paper-backed)Class A achievableDepends on fiber weight and backing
SisalClass A achievableDense fiber structure helps
CorkClass B typicalCork is naturally fire-resistant; some achieve Class A
Paper weaveClass A typicalLightweight, low fuel load
Vinyl (Type II)Class A typical when testedType II is a weight grade; Class A is a separate E84 result

Critical: Fire ratings are system-dependent — the same wallcovering may rate differently on different substrates or with different adhesives. Always use the specific test report for your product + substrate combination.

What About NFPA 255?

NFPA 255 was withdrawn in 2011. It was the National Fire Protection Association's equivalent of ASTM E84 — technically identical test method. Modern building codes now reference ASTM E84 or UL 723 exclusively. If you encounter old specifications referencing NFPA 255, update them to ASTM E84.

Is ASTM F793 or "Type II" a Fire Rating?

No. ASTM F793 classifies wallcoverings by use characteristics, and the commercial Type I / II / III grades that specifiers quote come from Federal Specification CCC-W-408 and Wallcovering Association W-101. They are minimum weights for vinyl wallcovering, not flame-spread results. A hotel specification that reads "Type II, Class A" is two separate requirements: a vinyl weight grade and an ASTM E84 result.

GradeMinimum weight (oz/sq yd)Per 54-inch linear yardIntended use
Type I (light duty)7 (industry practice 10)10.5 oz (15 oz)Ceilings, walls without scuffing
Type II (medium duty)1320 ozCorridors, lounges, offices — most commercial vinyl
Type III (heavy duty)2233 ozAreas hit by moving equipment

Source: CCC-W-408 / WA W-101 conversion table as reproduced in UFGS 09 72 00. Checked 2 September 2026.

Natural grasscloth, sisal and paperweave are not vinyl and are not graded by Type. Specify them by ASTM E84 class plus backing type and weight (for example, non-woven backing at 120 gsm or above), and ask for the E84 report on the exact backing you will receive.

Which Code Decides the Class You Need?

The International Building Code, Chapter 8 sets the required class for interior wall and ceiling finish by occupancy group and by location: exit enclosures, corridors and rooms are treated separately, and a sprinklered building is generally allowed one class lower. Hotels are Group R-1; hospitals are Group I-2; restaurants and assembly spaces are Group A. Your Authority Having Jurisdiction (AHJ) applies that table.

Some AHJs treat woven natural fibre as a textile wall covering under IBC Section 803, which then requires either an NFPA 286 room-corner test or a Class A E84 result in a sprinklered building. Ask which path the AHJ expects before you submit, because NFPA 286 is a full-scale test and takes longer to arrange. See the fire rating guide for the EN 13501 and GB 8624 equivalents.

How Do You Specify Fire Ratings?

  1. Check the building code: IBC Chapter 8 covers interior finishes — identify required class for your occupancy and building element
  2. Request the test report: the brand or buyer commissions the ASTM E84 test for their market; Grasscloths supplies samples, composition data and per-batch documentation so the lab tests the exact construction you will install
  3. Verify the substrate: The report must match your installation substrate (typically Type X gypsum board)
  4. Document in specifications: Reference the specific ASTM E84 class in your wallcovering specification — see specification guide
  5. Keep the report on file: Building inspectors may request it during construction

Frequently Asked Questions

Does natural wallcovering pass ASTM E84 Class A?

Many natural wallcoverings achieve Class A when adhered to gypsum board substrate. The rating depends on the specific material, backing and installation method. Request the test report from whoever commissioned the test, for the exact backing and substrate you will install.

Is NFPA 255 still valid?

No. NFPA withdrew NFPA 255 in 2011 because it was redundant with ASTM E84. Modern building codes reference ASTM E84 or UL 723 exclusively.

Who determines the required fire class for my project?

Your local Authority Having Jurisdiction (AHJ) and the applicable building code (typically IBC) determine the required class based on occupancy type and location within the building.

Does "Type II" mean Class A?

No. Type II is a vinyl weight grade (minimum 13 oz/sq yd, 20 oz per 54-inch linear yard, from CCC-W-408 and ASTM F793). Class A is an ASTM E84 flame-spread result (FSI 0–25). A specification can require one, both, or neither; natural wallcovering is specified by E84 class and backing weight rather than by Type.

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