Firestopping is an integral part of fire protection engineering. Firestop systems protect against the passage of flames, deadly gasses and toxic smoke through openings that are created for penetrations, joints and gaps in fire-resistive walls, floors and floor/ceiling assemblies. The integrity of fire-rated assemblies is restored by firestop systems.
Forestopping is a method of containing smoke and fire by establishing fire rated assemblies in construction and maintaining those barriers through fire rated caulks, motors, putties, intumenscent collars and intumescent pillows.
A firestop, when properly installed, does exactly as it says: stops the spread or advancement of fire from one section of a structure to another.
Firestopping systems are typically categorized by through-penetration of:
Flame Rating (F-rating)
The F-rating is expressed in hours and the number indicates the specific length of time that a barrier can withstand fire before being consumed or before permitting the passage of flame through the opening.
Thermal Rating (T-rating)
The T-rating is expressed in hours and the number indicates the length of time that a tempurature on the non-fire side of a penatrationdoes not exceed 325 °F (163 °C) above the ambient tempurature.
Smoke Rating (L-rating)
The L-rating is the amount of air or cold smoke that can leak through a penetration and the number indicated the amount of air per cubic feet per minute. L-rating is tested under a different pressure of 0.30 inches water column (75 pa) at 75°F and at 400°F.