Fire Resistance and Sound Control Design Manual CertainTeed Corporation P.O. Box Valley Forge, PA Professional: GYPSUM BOARD of penetration by a pressurized hose stream required in the fire test procedure for walls. Recessed wall fixtures such as medicine cabinets, or electrical, telephone. Examples include electrical, plumbing and mechanical items. When these service items penetrate through horizontal assemblies, protection is required to With gypsum construction the industry has developed unique fire-resistance rated construction The industry refers to these wall assemblies as shaft wall systems.