In residential structures, what is the maximum area in square feet that the concealed space can exceed without requiring draft stops?

In residential construction, the use of draft stops is essential to control the spread of fire and to manage smoke movement through concealed spaces, such as wall cavities and attic spaces. The National Electrical Code and the International Building Code provide guidelines regarding concealed spaces.

When a concealed space in a residential structure exceeds a certain area, the installation of draft stops becomes a requirement to help contain potential fire hazards. In this case, the maximum area that a concealed space can exceed without necessitating the installation of draft stops is 1000 square feet. This threshold is significant because it helps prevent uncontrolled fire spread by compartmentalizing larger areas into smaller sections, making it easier to manage fire safety.

The reasoning behind the 1000 square feet limit is rooted in fire safety regulations, which aim to protect the occupants and properties by ensuring that larger cavities are sufficiently compartmentalized. By keeping concealed spaces smaller than this threshold, the chance of rapid fire spread is reduced, contributing to the overall safety of the residential structure.