Masonry Noncombustible Construction

Construction Class 4

Overview

This Construction Brief will give you an overview of Verisk's Construction Class 4 – masonry class4pg2pic1 noncombustible construction. When you've completed this course, you will know what a Verisk report means when it says a building is masonry noncombustible construction. And you'll understand why a particular structure is—or isn't—masonry noncombustible.

Definition

Buildings with exterior walls of masonry—not less than four inches thick, or
Buildings with exterior walls of fire-resistive construction—with a rating of not less than one hour, and
Noncombustible or slow-burning floors and roofs—regardless of the type of insulation on the roof surface

Advantages of masonry noncombustible construction

Uses floors and roof supported by superior exterior bearing member
that provide for stability and are less likely to collapse during a fire
Uses materials that do not readily burn

Disadvantages of masonry noncombustible construction

Uses unprotected steel for interior members of floors and roof, and steel loses strength and becomes less stable and more damageable at high temperatures
Uses slow-burning materials that do burn—adding fuel to a fire