Putty Pads: Why, where, and when are they required?
Code requires fire barriers to hold back the products of combustion (flames, heat, smoke and gasses). Where electrical boxes penetrate one or both membranes of a fire rated wall they provide a direct path for heat to be transferred more readily through the assembly, and puttyFirestopping, non-hardening, compound designed to seal through-penetrations as well as certain membrane penetrations against the spread of fire, smoke and toxic gasses. pads act as a barrier to minimize temperature rise on the non-fireside of the wall.
Putty Pads are designed to be installed over the back of electrical boxes, and should be molded to cover fittings and "pie crusted" to form a seal against the drywall and stud. It is not necessary to fit the putty pad between the stud and the box.
According to code, putty pads are required where any one of the following conditions exists:
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