Lesson five in the BICSI/Iowa State telecom installation correspondence course focuses on fire-containment with firestop systems.
When installing cable on any project, you must consider fire containment. This means understanding the importance of firestopping. Technically speaking, the term firestop refers to the installation of "qualified" firestop materials in holes made through fire-rated floors, walls or ceilings for the penetration of pipes, cables or other construction/building, service/utility items. Since you often must create openings in existing walls and floors within buildings in this line of work, it's equally necessary that you safely close them.
Why is firestopping necessary? This practice buys you time, because fire and smoke typically spread through openings in walls, floors and ceilings. It also saves lives, protects critical systems and investments and serves as a building liability reinforcement. You should use firestop products to restore the opening to the original fire-rated integrity. Most common requirements are for 1-, 2- or 3 hr. In rare instances, you'll need a 4-hr to 6-hr rating.
As a cabling installer, you must use approved methods to restore any penetrations made during the installation to the original rating of the structure you're penetrating. You're also responsible to firestop any holes created by the removal of existing penetrations. The two basic types of penetrations are:
- A through penetration is a hole made in a fire-rated wall or floor to run pipes, cables or any type of building service, completely through from one side of the fire barrier to the other.
- A membrane penetration is a hole in one side of a fire-rated wall or floor for a single surface-barrier penetration. (i.e., an electrical outlet/switch box).
A third party must independently test all firestop materials to ensure functionality. Always install products according to the manufacturer's instructions based on independent testing, or you may be held legally and financially responsible.
This means you cannot substitute products that are not part of the qualified assembly; cannot add more of a product to get a higher rating; cannot add or change the type or location of penetrations; can be held personally responsible for improperly firestopping or not firestopping at all; and can contact the manufacturers to get written assistance for situations not covered in their installation practices for qualified assemblies.
The topic of firestop systems can be broken down even further into two broad categories: mechanical and nonmechanical.
Mechanical systems consist of manufactured elastomeric components pre-sized and shaped to fit around standard cables, tubes and conduits (Fig. 1). These products are made of several flexible substances that resemble rubber. These systems use mechanical pressure to hold the elastomeric components in place and provide a tight seal around the penetrating devices. Whether or not this includes frames, you must have some means of applying compression to the modules. The elastomeric modules are fitted around penetrating elements or arrayed within a flame.
Nonmechanical firestop systems are generally pliable. These include items such as putties, caulks, blankets, silicone foam and other types of materials that can be molded to fit into an opening to seal it.
Since all firestop products have unique properties to help contain the fire, each may contain one or more properties, including:
- A firestop that is endothermic can absorb heat. This prevents the temperature from rising on the other side of the fire barrier.
- A firestop that is intumescent will swell or enlarge when under the influence of heat (Fig. 2). The material swells around and within the penetration to provide a tight seal. In some applications, it's designed to crush the penetration, such as with combustible conduits.
- A firestop that is ablative develops a hard char that resists erosion from fire and flames. This allows a soft firestop to become rigid and to help it withstand the force from a hose stream (Fig. 3 on page 40).
When referring to firestopping systems, the terms qualified, tested, listed, classified and approved are essentially synonymous. Each refers to firestopping systems tested by an independent laboratory and certified as effective (different laboratories use different terms). For simplicity, this lesson uses the word qualified to represent all of these terms.
As they relate to firestopping, the terms system and design are nearly synonymous; both refer to an arrangement of specific firestopping materials in a specific configuration (See the table on page 38). Keep in mind, this lesson does not address local authorities' requirements concerning the design, use and specifications for these structures or assemblies. Consider the following guidelines before selecting a qualified firestopping solution for your specific application.
- Consider actual conditions tested/ covered by the system.
- When you are substituting one manufacturer's system for another's, make sure the firestop materials selected are appropriate for the actual conditions.
- Never substitute products of a qualified firestop system with another manufacturer's products. Products from one manufacturer's system are not interchangeable with products from another's.
- The difference between the actual floor/ceiling/wall thickness and conditions tested during qualification may affect listed F and T ratings. Generally, the thinner the qualified construction, the better the F and T performance may be if actual construction is thicker. The reverse may not be true.
- A firestop material capable of sealing against the passage of smoke and toxic gases through the penetration is desirable (Fig. 4).
Most importantly, you should select a qualified firestop system that matches the actual conditions that exist (i.e., penetrating item(s), material, wall/floor/ceiling configuration). If you cannot make an exact match between firestop systems listed and actual conditions, select a system that's close and seek an engineering judgment by a qualified local authority having jurisdiction.
This correspondence course is offered in conjunction with BICSI, but is not directly sponsored by the organization. The intent of the course is to help students prepare for the written portion of the BICSI Installer Registration Program. This BICSI program also requires hands-on training, which is outside the scope of this correspondence course. This course is also offered as continuing education for those already registered as a BICSI apprentice, installer or technician.
STRUCTURED WIRING SYSTEMS MAKE INROADS With the growing use of the Internet, the wider application of PCs for schools and offices and the use of entertainment systems, residential wiring needs are changing fast.
According to Cahners In-Stat Group, Scottsdale, Ariz., a high-tech market research firm, response to these changing needs will create a residential structured wiring market that will exceed $1.4 billion by 2004. A structured wiring solution brings voice, data and video services to a central distribution center or hub.
The components of a structured wiring system use more expensive materials than the plain old telephone system (so-called POTS) wiring. This includes Cat. 5 twisted-pair (for voice and data). The recommended Cat. 5 cabling can support a local area network (LAN) and can transfer data at a speed of 100 megabytes per second.
RG-6 coaxial cable (for video) replaces RG-59, coaxial cable. The RG-6 cables, which are a replacement for the older RG-59 type cable, are routed to selected ports throughout the house, allowing each TV to receive its own signal or share it with other TV or computer monitors. Whether standard or optional, the hub enhances a structured wiring system, making it easier to install LANs and additional cabling for extra telephone lines, fax and data lines from a centralized location. Maintenance and repair are made easier.
BICSI OFFERS VIDEO TOURS FOR STRUCTURED CABLING TAMPA, Fla. - BICSI, the international telecommunications association, announces its new video-based training, "Introduction to Commercial Voice/Data Cabling Systems." Designed to provide a general knowledge of commercial telecommunications cabling, the video visually explains structured cabling systems through a narrated tour of installations in both large and small facilities.
The video provides an overview of building pathways and spaces, codes and standards, electrical protection and copper and fiber cabling media. The narrator and BICSI Master Instructor inspect cabling infrastructure components in a real-world setting. Accompanying study guide/workbooks allow students to review diagrams and key points in more detail.
For more information on the video, call BICSI at (800) 242-7405 or (813) 979-1991.