Firestop
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A firestop or fire-stopping is a form of passive fire protection that is used to seal around openings and between joints in a fire-resistance-rated wall or floor assembly. Firestops are designed to maintain the fire-resistance rating of a wall or floor assembly intended to impede the spread of fire and smoke.[1]
Description
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.[2][3] 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.)
Materials
Components include
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Fire test of mortar-based firestop
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Pipewith metallic piping penetrations in a 2-hour fire-resistance rated concrete floor slab
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Inadequate firestop with rockwool
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Construction drawing of a firestop
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Firestop mortar seal of a cable tray
Maintenance
Firestops should be maintained in accordance with the
Ratings
Firestop materials are not
Testing and certification
Certification listings include those available from:
- Underwriters Laboratories
- Underwriters Laboratories of Canada
- Deutsches Intitut für Bautechnik (Germany)
FIRAS scheme- Warrington Fire (UK)
- Efectis (Netherlands, France, and Norway)
- FM Global[4]
Regulations and compliance
When the installed configuration does not comply with the appropriate certification listing, the fire-resistance rating may be lower than expected. Each opening in a fire-resistance-rated wall or floor in a building must have a certification listing. There are thousands of listings from various certification and testing laboratories. The Canadian and United States Underwriters Laboratories publish books listing firestop manufacturers who have contracted with them for testing and certification.
Inadequate firestopping
No firestopping
Older buildings often lack firestops. A thorough inspection can identify all vertical and horizontal fire barriers and their fire ratings, and all breaches in these barriers (which can be sealed with approved methods).
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Unsealed pipe penetration in two-hour fire-resistance rated concrete block wall
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Improper breach of fire-resistance rated drywall assembly
Non-listed attempts
Firestops created by contractors or building maintenance personnel which are not listed are not credited with an adequate fire resistance rating for building-code compliance purposes. They are usually short-term, cost-cutting measures at the expense of fire safety and code compliance. One common error is citing a listing for a product which may be for another use. An insulation with an active listing of a certain flame-spread rating is unacceptable for firestopping purposes.
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Stuffed fiberglass insulation would rapidly melt and fall out in a fire.
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Spray fireproofing improperly used to cover penetrations
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Polyurethane foam used to fill aBrowns Ferry Nuclear Power Plant, this type of seal resulted in significant fire damage.
See also
References
- ^ "Fire Stopping: What Every Contractor Needs to Know | EC Mag". www.ecmag.com. Archived from the original on 2017-09-07. Retrieved 2017-09-06.
- ^ "3M Technical Library/Technical Bulletins". 3M.
- ^ "Firestop Contractors International Association Technical-Resources". fcia.com.
- ^ http://www.fmglobal.com/assets/pdf/fmapprovals/4991.pdf Approval Standard for Approval of Firestop Contractors, Class Number 4991
External links
- Gütegemeinschaft Brandschutz im Ausbau Archived 2012-11-21 at the Wayback Machine German passive fire protection association
- International Firestop Council An International association of firestop manufacturers, consultants, inspectors, and contractors
- Efectis Test Laboratory
- UL and International Firestop Council (IFC) video Close enough is not good enough: A demonstration of Proper vs Improper Firestopping
- UL Essay On Firestops
- Deutsches Institut für Bautechnik (DIBt)
- iBMB a part of Technische Universität Braunschweig
- Underwriters' Laboratories of Canada (ULC)
- Underwriters Laboratories