R302.3.1

Section R302.3.1 is titled 'Supporting construction' and covers the requirements for two-family dwelling fire-resistance rated construction. The requirement that supporting construction for fire-resistance-rated assemblies between two-family dwelling units meets or exceeds the fire-resistance rating of the assembly it is supporting is established. The purpose of this section is to prevent premature structural failure of a fire-resistance-rated assembly in the event of a fire.

The model shows an x-rayed skin of a two-family dwelling with highlighted assemblies which are fire-resistance rated to separate the units and the supporting construction for those assemblies highlighted in a different color.