Angkop Corp / Technical Reference / ASTM E84

Fire performance.
Properly scoped.

A concise reference for AEC teams reviewing Flexible Natural Stone™ surface-burning performance. Use the applicable product test report, adopted code edition, and authority-having-jurisdiction requirements for the actual project.

01 / Classification

ASTM E84 Class A.

Standard

ASTM E84Surface Burning Characteristics of Building Materials.

Classification

Class AWhere identified by the applicable product test report.

Reported indices

FSI ≤ 25 / SDI ≤ 450Review the current report for the specified product and configuration.

Scope: ASTM E84 is a surface-burning classification. It is not a blanket fire-resistance rating, fireproofing claim, or approval of a complete wall, ceiling, fireplace, or exterior assembly.

02 / What the test measures

Two indices. One material-surface reference.

Flame Spread Index / FSI

How quickly flame travels.

FSI describes the rate at which flame travels across the tested material surface. Lower values indicate slower flame propagation under the defined test conditions.

Smoke Developed Index / SDI

How much smoke develops.

SDI describes the optical density of smoke generated during the test period. It is evaluated independently from flame spread.

Class	Flame Spread Index	Smoke Developed Index
Class A	0–25	0–450
Class B	26–75	0–450
Class C	76–200	0–450

03 / Assembly responsibility

A surface result does not replace a rated assembly.

Flexible Natural Stone™ is a surface finish material. The underlying wall, floor, or ceiling assembly must independently satisfy any required fire-resistance rating, including the required framing, substrate, insulation, barriers, and penetrations.

For specification teams.

Confirm the specified panel, substrate, adhesive, clearances, and installation condition. Verify the adopted code edition and local amendments with the authority having jurisdiction. Firestopping and rated penetrations remain assembly responsibilities.

04 / Documentation