What is meant by "percent compression" in firestop systems?

"Percent compression" in firestop systems refers to the percentage change in size of the firestop material when it is mechanically compressed. This characteristic is essential for understanding how firestop materials behave under pressure, particularly how they maintain their integrity and effectiveness in sealing joints and penetrations. Firestop systems are designed to prevent the spread of fire, smoke, and toxic gases through openings in fire-rated assemblies, and their performance can be significantly affected by their ability to maintain a proper seal when subjected to movement or compression.

The comprehension of percent compression assists in selecting the right materials for specific applications, ensuring that they can adapt to changes in joint sizes without compromising their performance. This adaptability is crucial in maintaining the firestop's function over time, especially in dynamic environments where thermal expansion and contraction may occur.

Other concepts like joint width filling, the amount of sealant used, and the ratio of material to joint depth are relevant to firestop applications, but they do not specifically define percent compression as it pertains to the behavior of the material when compressed. Understanding the mechanics of percent compression ultimately contributes to better installation practices and improved safety outcomes in fire-rated applications.