ANSI FM 4473-2011 PDF

Full title and description

ANSI/FM 4473-2011 — Impact Resistance Testing of Rigid Roofing Materials by Impacting with Freezer Ice Balls. This test standard defines procedures, specimen preparation, and pass/fail criteria for assessing the resistance of prepared rigid roofing materials (tiles, planks and similar rigid roof coverings) to impacts produced by freezer ice balls intended to simulate hail.

Abstract

Provides a laboratory method that uses frozen ice spheres (freezer ice balls) propelled at controlled velocities to deliver defined kinetic energies to roofing samples. The procedure is intended primarily for steep‑slope rigid roofing materials and establishes classification limits (including a Class 4 level) and reporting requirements to determine whether a material resists impact without cracking, splitting or other failure.

General information

• Status: Current (listed as the active FM/ANSI test standard; also maintained by FM Approvals).
• Publication date: 2011 (designated ANSI/FM 4473-2011).
• Publisher: Factory Mutual Research Corporation / FM Approvals (ANSI-designated adoption).
• ICS / categories: Roofing and roof coverings / impact testing (ICS classification often listed under building materials/testing categories such as 91.060.20).
• Edition / version: ANSI/FM 4473-2011 (published 2011); FM Approvals has published a consolidated designation showing the 2011 standard with an R2020 update notation in distributor listings.
• Number of pages: Distributor listings vary (commonly shown as 10 pages in some catalogs; alternative listings show 16 pages depending on formatting).

Scope

Specifies a laboratory impact‑test method using freezer ice balls to evaluate the impact resistance of new prepared rigid roofing materials primarily for steep‑slope roof systems. The scope covers ice‑ball preparation, specimen mounting and conditioning, impact locations and sequence, acceptance criteria and test reporting. The standard is intended to simulate the dynamic effects of hail and to classify materials by resistance level (including a maximum Class 4 for 2.0‑inch ice spheres at specified impact energies).

Key topics and requirements

• Preparation and conditioning of freezer ice balls (size, temperature and integrity requirements).
• Specimen dimensions, substrate mounting and representative mounting conditions for rigid roofing products.
• Defined impact locations on the specimen (field, fastener/lap, edge) and number of impacts per location.
• Impact energy/velocity targets corresponding to classification levels (Class ratings up to Class 4, with 2.0‑inch ice ball impacts used for the highest class in the standard).
• Pass/fail criteria describing allowable damage (cracking, splitting, puncture) and reporting requirements for test results and observations.
• Instructions for test reporting, data recording and documentation necessary for product evaluation and approval.

Typical use and users

Used by independent test laboratories, roofing manufacturers and product developers to determine hail/impact resistance classifications for rigid roof coverings; by FM Approvals, insurers and certifying bodies for product approval and listing; and by architects, specifiers and code officials to compare product performance and support product selection in hail‑prone regions. Research groups and standards committees may also use the method as a basis for adaptations to low‑slope roofing or PV module testing.

Related standards

Commonly referenced alongside UL 2218 (Impact Resistance of Prepared Roof Covering Materials), FM Approvals 4470/4475 (related FM approval standards for roof systems and steep‑slope covers), and various ASTM roofing test methods (for wind and related performance). Several research and approval programs compare or combine results from ANSI/FM 4473 and steel‑ball impact tests when assessing hail susceptibility.

Keywords

Freezer ice ball; hail simulation; impact resistance; rigid roofing materials; FM 4473; ANSI/FM; Class 4; roofing test; product approval; FM Approvals.

FAQ

Q: What is this standard?

A: ANSI/FM 4473-2011 is an FM/ANSI test standard that describes a laboratory method using frozen ice spheres to assess the impact resistance of rigid roofing materials and to classify their performance under simulated hail impacts.

Q: What does it cover?

A: It covers ice‑ball preparation, specimen mounting and conditioning, defined impact locations and energies, pass/fail acceptance criteria, and reporting procedures for rigid steep‑slope roofing products. The method produces product classifications (e.g., Class 4 for the most severe prescribed ice‑ball impact level).

Q: Who typically uses it?

A: Independent test laboratories, roofing manufacturers, FM Approvals and other certifying organizations, product developers, architects and insurers use the standard for testing, approval and specification of hail‑resistant rigid roofing materials.

Q: Is it current or superseded?

A: The 2011 designation (ANSI/FM 4473-2011) is the published standard year; distributor and approval listings identify the standard as current. Some FM Approvals/distributor records also show the 2011 standard with a reconciliation or R2020 notation (FM 4473-2011 (R2020)) indicating a 2020 reaffirmation or editorial update in vendor/approval records—users should confirm the exact version/errata with FM Approvals or the official approval guide before citing in a formal approval submission.

Q: Is it part of a series?

A: It is commonly used with other FM Approval documents and roofing standards (for example FM 4470/FM 4475) and is part of the family of FM/ANSI methods and related industry tests (UL 2218, ASTM test methods) used to evaluate roof cover performance.

Q: What are the key keywords?

A: Freezer ice ball, hail impact, impact resistance, rigid roofing, FM 4473, ANSI/FM, Class 4, test method, roof cover approval.