What is the minimum requirement for the thickness of gypsum board separating garages located below a habitable room?

The requirement for the thickness of gypsum board separating garages from habitable spaces is set to ensure adequate fire resistance and safety. A thickness of 5/8 inch is specified for this application, as it provides the necessary fire protection and helps to contain smoke and flames in the event of a fire originating in the garage. This is particularly important when considering that garages often contain flammable materials and vehicles, which could pose significant fire hazards to the living spaces above.

Using 5/8 inch gypsum board meets the standards typically outlined in building codes, recognizing the need to protect habitable areas from potential fire risks. Thicker boards, such as those at 3/4 inch or 1 inch, may provide additional fire resistance but are not required per code for this specific application, while thinner options like 1/2 inch do not offer sufficient protection. Thus, 5/8 inch is established as the minimum standard that balances safety and practicality.