Draftstopping must be provided in attics and concealed roof spaces for which types of residential occupancy groups?

Draftstopping is a crucial fire safety measure employed in attics and concealed roof spaces to limit the movement of smoke and flames during a fire. For residential occupancy groups, the requirements for draftstopping typically apply specifically to certain categories.

In the context of R-1 and R-2 buildings, both of these occupancy types can often include multiple dwelling units, which presents a higher risk in terms of fire spread. R-1 buildings typically house transient occupants, such as hotels or motels, while R-2 buildings consist of multiple dwelling units, including apartments with three or more units.

The necessity for draftstopping in these structures stems from the need to compartmentalize spaces and prevent smoke migration, enhancing life safety for residents and enabling better smoke control in the event of a fire. Therefore, both R-1 and R-2 buildings, particularly those with three or more units, necessitate draftstopping in their design to adhere to fire safety standards and regulations.

This requirement ensures that effective measures are in place to protect residents, as well as to maintain structural integrity during a fire incident. Thus, the correct answer encompasses both types of occupancy, underscoring the importance of draftstopping in promoting fire safety across various residential settings.