A firestop or fire-stopping is a form of

passive fire protection Passive fire protection (PFP) is components or systems of a building or structure that slows or impedes the spread of the effects of fire or smoke without system activation, and usually without movement. Examples of passive systems include floor- ...

that is used to seal around openings and between

joints A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...

in a fire-resistance-rated wall or floor assembly. Firestops are designed to maintain the

fire-resistance rating A fire-resistance rating typically means the duration for which a passive fire protection system can withstand a standard fire resistance test. This can be quantified simply as a measure of time, or it may entail other criteria, involving evide ...

of a wall or floor assembly intended to impede the spread of fire and smoke.

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. 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

intumescent An intumescent is a substance that swells as a result of heat exposure, leading to an increase in volume and decrease in density. Intumescent materials are typically used in passive fire protection and require listing, approval, and compliance in ...

s, cementitious mortars, silicone, firestop pillows,

mineral fibers In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ...

, and

rubber Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, a ...

compounds. File:Test in flight.jpg, alt=See caption,

Fire test A fire test is a means of determining whether fire protection products meet minimum performance criteria as set out in a building code or other applicable legislation. Successful tests in laboratories holding national accreditation for testing and ...

of mortar-based firestop File:Sl silicone pipe covering.jpg, alt=See caption,

Pipe Pipe(s), PIPE(S) or piping may refer to: Objects * Pipe (fluid conveyance), a hollow cylinder following certain dimension rules ** Piping, the use of pipes in industry * Smoking pipe ** Tobacco pipe * Half-pipe and quarter pipe, semi-circul ...

with metallic piping penetrations in a 2-hour fire-resistance rated concrete floor slab File:Stuffed rockwool firestop.jpg, alt=Insulated pipes, Inadequate firestop with rockwool File:Penetrations through firestop.svg, alt=See caption, Construction drawing of a firestop File:Mortar tag.jpg, alt=Curved wires passing through insulation, Firestop mortar seal of a

cable tray In the electrical wiring of buildings, a cable tray system is used to support insulated electrical cables used for power distribution, control, and communication. Cable trays are used as an alternative to open wiring or electrical conduit syste ...

Maintenance

Firestops should be maintained in accordance with

listing and approval use and compliance Listing and approval use and compliance is the practice of installing and operating safety-related products and materials in accordance with to minimum performance conformance testing requirements. The conformance could be for a certification li ...

. Construction documentation sometimes includes an inventory of all firestops in a

building A building, or edifice, is an enclosed structure with a roof and walls standing more or less permanently in one place, such as a house or factory (although there's also portable buildings). Buildings come in a variety of sizes, shapes, and funct ...

, with drawings indicating their location and certification listings. Using this, a building owner can meet the

fire code Fire safety is the set of practices intended to reduce the destruction caused by fire. Fire safety measures include those that are intended to prevent the ignition of an uncontrolled fire and those that are used to limit the development and ef ...

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.

Tagging

Proper maintenance is enhanced by the installation of tags on each side of the firestop with information needed to refer to documents indicating approved procedures for the original installation and re-entries. This requires knowledge of the certification listing used for each opening of a building joint or a penetrant through-penetration seal. File:Firestop tag front.jpg, alt=See caption, Firestop tag front, with information needed for proper maintenance File:Firestop tag back.jpg, alt=See caption, Tag back, for recording maintenance

Ratings

Firestop materials are not rated 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 of

caulking Caulk or, less frequently, caulking is a material used to seal joints or seams against leakage in various structures and piping. The oldest form of caulk consisted of fibrous materials driven into the wedge-shaped seams between boards on ...

over packed

mineral wool Mineral wool is any fibrous material formed by spinning or drawing molten mineral or rock materials such as slag and ceramics. Applications of mineral wool include thermal insulation (as both structural insulation and pipe insulation), f ...

. The arrangement, not the caulking, provides the two-hour rating. The individual firestop materials and the overall firestop assembly are listed.

Testing and certification

Certification listings include those available from: *

Underwriters Laboratories The UL enterprise is a global safety science company headquartered in Northbrook, Illinois, composed of three organizations, UL Research Institutes, UL Standards & Engagement and UL Solutions. Established in 1894, the UL enterprise was founded as ...

* Underwriters Laboratories of Canada * Deutsches Intitut für Bautechnik (

Germany Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the sou ...

) FIRAS scheme- Warrington Fire (UK) * Efectis (

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan ar ...

, and

Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...

) *

FM Global FM Global is an American mutual insurance company based in Johnston, Rhode Island, United States, with offices worldwide, that specializes in loss prevention services primarily to large corporations throughout the world in the ''Highly Protecte ...

http://www.fmglobal.com/assets/pdf/fmapprovals/4991.pdf Approval Standard for Approval of Firestop Contractors, Class Number 4991

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 The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

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). File:Unsealed1.jpg, alt=Two pipes going through an open wall, Unsealed pipe penetration in two-hour fire-resistance rated concrete block wall File:Cambrian college no firestop 1.jpg, alt=Pipes going through a wall with gaps, Improper breach of fire-resistance rated

drywall Drywall (also called plasterboard, dry lining, wallboard, sheet rock, gypsum board, buster board, custard board, and gypsum panel) is a panel made of calcium sulfate dihydrate (gypsum), with or without additives, typically extruded between thi ...

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 Fire safety is the set of practices intended to reduce the destruction caused by fire. Fire safety measures include those that are intended to prevent the ignition of an uncontrolled fire and those that are used to limit the development and ef ...

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. File:Concrete firestop.jpg, alt=Cables with a concrete seal, Common

concrete Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most ...

, with no testing intended for certification listing File:Stuffed fibreglass firestop.jpg, alt=Cables routed through fiberglass insulation, Stuffed fiberglass insulation would rapidly melt and fall out in a fire. File:Cambrian college fireproofing delamination 5.jpg, alt=Green-tinted photo of metal sprayed with plaster, some of which has flaked off, Spray fireproofing improperly used to cover penetrations File:Puf.jpg, alt=See caption, Polyurethane foam used to fill a

penetration; at Browns Ferry Nuclear Power Plant, this type of seal resulted in significant fire damage.

References

External links

Gütegemeinschaft Brandschutz im Ausbau
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

Deutsches Institut für Bautechnik (DIBt)

iBMB
a part of Technische Universität Braunschweig
Underwriters' Laboratories of Canada (ULC)

Underwriters Laboratories
{{HVAC, state=collapsed Building materials Passive fire protection