UL 618 PDF

1 Scope

1.1 These requirements cover concrete masonry units for use in fire resistive walls in accordance with the conditions of acceptance of the Standard for Fire Tests of Building Construction and Materials, UL 263.

1.2 Concrete masonry units are rated as follows:

1. a) 2-hour units are intended for use in fire resistive walls having a rating of 2 hours or less.

2. b) 3-hour units are intended for use in fire resistive walls having a rating of 3 hours or less.

3. c) 4-hour units are intended for use in fire resistive walls having a rating of 4 hours or less.

Summary of Topics

This Tenth Edition of ANSI/UL 618 dated November 4, 2024 includes updated Referenced Publications, Section 4, and editorial updates throughout the Standard.