防火板可防止防火等级的墙壁或地板组件中未受保护的水平和垂直穿透形成一条火和烟可以传播的路线，否则这本来是防火结构，例如。管道穿过防火墙的地方。 防火也是密封防火结构之间的间隙，例如。墙壁和上面的地板之间的线性间隙，以便建筑形成一个完整的防火和烟雾扩散屏障。 开口类型 编辑 阻火材料用于： 电气、机械和结构穿透 未穿透的开口（例如供将来使用的开口） 重新进入现有的防火板 在防火等级的墙壁或地板组件中控制或摆动接头 防火等级的墙壁或地板组件之间的连接 墙头(HOW) 接头，非承重墙组件与地板组件相遇的地方 数字字符用于识别在本系统中可以找到什么渗透剂（如果有的话），并帮助识别所使用的 UL 测试系统。 穿透分类及其穿透的屏障，按照所有防火产品制造商采用的标准化字母数字系统进行分类。 一个典型的系统由几个字母组成，后跟一系列数字，表示通过特定屏障的渗透剂类型，例如：（FB-5533。）

Firestops prevent unprotected horizontal and vertical penetrations in a fire-resistance-rated wall or floor assembly from creating a route by which fire and smoke can spread that would otherwise have been fire resisting construction, e.g. where a pipe passes through a firewall.

Fire stopping is also to seal around gaps between fire resisting constructions, e.g. the linear gap between a wall and the floor above, in order for construction to form a complete barrier to fire and smoke spread.

Opening types

Firestops are used in:

• Electrical, mechanical, and structural penetrations
• Unpenetrated openings (such as openings for future use)
• Re-entries of existing firestops
• Control or sway joints in fire-resistance-rated wall or floor assemblies
• Junctions between fire-resistance-rated wall or floor assemblies
• Head-of-wall (HOW) joints, where non-load-bearing wall assemblies meet floor assemblies

Numeric characters are used to identify what penetrant, if any, can be found within the present system and help identify what UL-tested system was used.

Classification for penetrations and the barriers they penetrate, are categorized by a standardized letter-number system that has been adopted by all firestop products manufacturers. A typical system would consist of several letters, followed by a series of numbers indicating the type of penetrant that is passing through the particular barrier ex: (FB-5533.)