What is a party wall, and how is it typically treated in the IRC?

A party wall is defined as a shared wall that serves as a common boundary between two adjoining properties, typically in the context of multi-family homes, townhouses, or any structures that are built side by side. In the International Residential Code (IRC), party walls must comply with specific fire-resistance requirements to minimize the risk of fire spread between units that share the wall. This includes maintaining certain ratings for materials used in the construction of the wall, ensuring that both sides have adequate protection.

This focus on fire-resistance is crucial because it helps to protect the occupants of both sides of the wall, thereby enhancing safety by preventing flames, heat, and smoke from traversing the shared wall into an adjacent unit. The IRC outlines these provisions to ensure that residential buildings provide an acceptable level of safety to their occupants, which is a key aspect of building codes.

The other options do not accurately describe a party wall in the context of the IRC; for example, stating that it collapses easily does not reflect the structural integrity expected from a party wall, and characterizing it as decorative ignores its functional and safety aspects. Additionally, it is not exclusive to multi-story buildings; party walls can also be found in single-family attached homes.