The test fixture in which the assembly is mounted shall consist of the wood stud construction described in Section 12-3-5.2.2. Systems that require a specific mounting arrangement not represented by these test fixtures, such as masonry or brick, shall be mounted in a fixture of equivalent dimensions and rigidity, as described in the installation instructions. If agreeable to the testing laboratory and manufacturer, the wood stud fixture shall be representative of all mounting structures, provided the system is securely held in place in the fixture during all tests.
The entire test fixture shall be constructed of commercially available two by four trade size vertical wood studs [nominal 1.5 inches by 3.5 inches (38.1 mm by 89 mm)], spaced on maximum 16 inch (406 mm) centers. The opening shall be framed with two by four plates and minimum two layers of two by four for headers. For window openings, a minimum of two layers of two by four shall be used for the sill and cripple studs shall be provided. The frame shall be secured in place so it does not move when the system is subjected to the test forces noted below. The frame shall extend a minimum of 12 inches (305 mm) above and on each side of the opening.
Actual doors and windows or their frames shall not be required to be mounted in the opening unless the presence of such doors, windows or frames affects the operation of the system, or unless part of the system is mounted on the door or window frame.
The exterior side of the assembly shall be covered by 3/4-inch (19 mm) thick trade size CDX plywood, secured with minimum 11/2-inch (38 mm) nails or screws, secured at least every 12 inches (305 mm) to each stud, sill and header. The interior side of the assembly shall be covered with a layer of 1/2-inch (13 mm) gypsum wallboard, secured with minimum 11/4-inch (32 mm) nails or screws at least every 12 inches (305 mm) to each stud, sill and header.
Openings in the test fixture shall be sized to accommodate the size of the assembly under test, as described in the installation instructions. Opening size shall be allowed to vary if the size used is judged to not affect the results of any test performed.