Owens corning 15 in.
Fire blocking insulation.
F ire blocking aims to prevent or at least slow the vertical movement of flames smoke and gases by sealing off concealed spaces like stud cavities and soffits.
Smoke and gases readily travel horizontally as well so preventing horizontal air movement such as within a dropped ceiling has its own name.
Insulation materials fire block insulation and foam fiberglass insulation secured tightly batts or blankets insulation cellulose insulation at approved thickness spray foams that are approved for fire blocking.
Fire block and firestop are two different concepts and use different materials.
Rockwool comfortboard 80 is a rigid mineral wool insulation sheathing board that is non combustible water repellent fire resistant and sound absorbent.
When piping conduit or similar obstructions are encountered the insulation shall be packed tightly around the obstruction.