 | This article has multiple issues. Please helpimprove it or discuss these issues on thetalk page.(Learn how and when to remove these messages) (Learn how and when to remove this message)
|
Afirestop or fire-stopping is a form ofpassive fire protection that is used to seal aroundopenings and betweenjoints in afire-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]
Firestops prevent unprotected horizontal and vertical penetrations in afire-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 afirewall.
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.
Firestops are used in:
Numeric characters are used to identify what penetrant, if any, can be found within the present system and help identify whatUL-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.)
Components includeintumescents,cementitious mortars,silicone,firestop pillows,mineral fibers, andrubber compounds.
Firestops should be maintained in accordance with thecertification listing. Construction documentation sometimes includes an inventory of all firestops in abuilding, with drawings indicating their location and certification listings. Using this, a building owner can meet thefire code relating to fire barriers. Improper repairs may otherwise result, which would violate the fire code and could allow a fire to travel between areas intended by code to be separated during a fire.
Firestop materials are notrated per se. They receive a fire rating by combining materials in an arrangement specific to the item (a pipe or cable, for example) penetrating the fire-rated wall or floor and the construction arrangement of the fire-rated wall or floor. A two-hour-rated pipe-penetration firestop may consist of a layer ofcaulking over packedmineral wool. The arrangement, not the caulking, provides the two-hour rating. The individual firestop materials and the overall firestop assembly arelisted.
Certification listings include those available from:
FIRAS scheme- Warrington Fire (UK)
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 andUnited States Underwriters Laboratories publish books listing firestop manufacturers who have contracted with them for testing and certification.
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).
Firestops created by contractors or building maintenance personnel which are notlisted 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 offire 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.
