Penetration (firestop)

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A penetration, in firestopping, is an opening, such as one created by the use of a cast-in-place sleeve, in a wall or floor assembly required to have a fire-resistance rating, for the purpose of accommodating the passage of a mechanical, electrical or structural penetrant. The penetration may or may not contain a firestop system. A penetration is not a penetrant. A penetration may or may not include a penetrant.

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 fireproofing of a wall or floor assembly allowing it to impede the spread of fire and smoke.

Sleeve (construction) pipe or cable connector

In construction, a sleeve is used both by the electrical and mechanical trades to create a penetration.

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 a host of other criteria, involving other evidence of functionality or fitness for purpose.


Old terminology

The nuclear industry in particular used to refer to firestops as "penetration seals" or "penseals". These terms are superseded by the term firestop. Whereas penetration seals or penseals only dealt with openings made to accommodate penetrants, firestops now also include Joint (building).

Penetrant (mechanical, electrical, or structural)

Penetrants, or penetrating items, are the mechanical, electrical or structural items that pass through an opening in a wall or floor, such as pipes, electrical conduits, ducting, electrical cables and cable trays, or structural steel beams and columns. When these items pierce a wall or floor assembly, they create a space between the penetrant and the surrounding structure, which can become an avenue for the spread of fire between rooms or floors. Modern building codes generally require a service penetration firestop to seal the openings around penetrants, in order to restore the fire-resistance rating of the parent assembly.

A building joint is a junction where building elements meet without applying a static load from one element to another. When one or more of these vertical or horizontal elements that meet are required by the local building code to have a fire-resistance rating, the resulting opening that makes up the joint must be firestopped in order to restore the required compartmentalisation.

Why the term "Penetration (firestop)"?

It is useful to have clarity in construction communications, to differentiate between the opening, whether sealed or not, and the penetrants, which are optional components of a penetration, as sometimes openings (penetrations of the fire barrier) are created for future use, especially in electrical service rooms. A firestop, after all, tends to be easier to remove than concrete, which requires coredrilling equipment, cooling water, etc. A firestopped penetration may also be referred to as a firestop, as a firestop, by definition, is a system. Therefore, the terms firestop and penetration can at times be deemed to be interchangeable.

Construction Process of the building or assembling of a building or infrastructure

Construction is the process of constructing a building or infrastructure. Construction differs from manufacturing in that manufacturing typically involves mass production of similar items without a designated purchaser, while construction typically takes place on location for a known client. Construction as an industry comprises six to nine percent of the gross domestic product of developed countries. Construction starts with planning, design, and financing; it continues until the project is built and ready for use.

Concrete Composite construction material

Concrete, usually Portland cement concrete, is a composite material composed of fine and coarse aggregate bonded together with a fluid cement that hardens over time—most frequently a lime-based cement binder, such as Portland cement, but sometimes with other hydraulic cements, such as a calcium aluminate cement. It is distinguished from other, non-cementitious types of concrete all binding some form of aggregate together, including asphalt concrete with a bitumen binder, which is frequently used for road surfaces, and polymer concretes that use polymers as a binder.

A system is a group of interacting or interrelated entities that form a unified whole. A system is delineated by its spatial and temporal boundaries, surrounded and influenced by its environment, described by its structure and purpose and expressed in its functioning.


Sheet metal metal formed by an industrial process into thin, flat pieces

Sheet metal is metal formed by an industrial process into thin, flat pieces. Sheet metal is one of the fundamental forms used in metalworking and it can be cut and bent into a variety of shapes. Countless everyday objects are fabricated from sheet metal. Thicknesses can vary significantly; extremely thin sheets are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are considered plate steel or "structural steel."

See also

Passive fire protection integral component of the three components of structural fire protection and fire safety in a building; does not require a certain amount of motion and response in order to work

Passive fire protection (PFP) is an integral component of the components of structural fire protection and fire safety in a building. PFP attempts to contain fires or slow the spread, such as by fire-resistant walls, floors, and doors. PFP systems must comply with the associated listing and approval use and compliance in order to provide the effectiveness expected by building codes.

Annulus (firestop) the space between a penetrant and whatever surrounds it

The annulus, or annular space, is the space between a penetrant and whatever surrounds it, such as the sides of an opening or a sleeve, as the case may be.

Firestop pillow

Firestop pillows are passive fire protection items, used for firestopping holes in wall or floor assemblies required to have a fire-resistance rating. The products must be used in accordance with a valid certification listing, subject to listing and approval use and compliance.

Nuclear Regulatory Commission United States government agency

The Nuclear Regulatory Commission (NRC) is an independent agency of the United States government tasked with protecting public health and safety related to nuclear energy. Established by the Energy Reorganization Act of 1974, the NRC began operations on January 19, 1975 as one of two successor agencies to the United States Atomic Energy Commission. Its functions include overseeing reactor safety and security, administering reactor licensing and renewal, licensing radioactive materials, radionuclide safety, and managing the storage, security, recycling, and disposal of spent fuel.

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Firewall (construction) barrier used to prevent the spread of fire through or between structures

A firewall is a fire-resistant barrier used to prevent the spread of fire for a prescribed period of time. Firewalls are built between or through buildings, structures, electrical substation transformers, or within an aircraft or vehicle.

Penetration may refer to:

Mortar (masonry) workable paste used to bind building blocks

Mortar is a workable paste used to bind building blocks such as stones, bricks, and concrete masonry units, fill and seal the irregular gaps between them, and sometimes add decorative colors or patterns in masonry walls. In its broadest sense mortar includes pitch, asphalt, and soft mud or clay, such as used between mud bricks. Mortar comes from Latin mortarium meaning crushed.

Bulkhead (partition) partition in a ship

A bulkhead is an upright wall within the hull of a ship or within the fuselage of an aeroplane. Other kinds of partition elements within a ship are decks and deckheads.

This page is a list of construction topics.

Fireproofing passive fire protection measure

Fireproofing is rendering something resistant to fire, or incombustible; or material for use in making anything fire-proof. It is a passive fire protection measure. "Fireproof" or "fireproofing" can be used as a noun, verb or adjective; it may be hyphenated ("fire-proof").

An intumescent is a substance that swells as a result of heat exposure, thus increasing in volume and decreasing in density. Intumescents are typically used in passive fire protection and require listing, approval and compliance in their installed configurations in order to comply with the national building codes and laws.

Within the context of building construction and building codes, "occupancy" refers to the use, or intended use, of a building, or portion of a building, for the shelter or support of persons, animals or property. A closely related meaning is the number of units in such a building that are rented, leased, or otherwise in use. Lack of occupancy, in this sense, is a "vacancy".

Cable tray Electrical cable supporting structure

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 systems, and are commonly used for cable management in commercial and industrial construction. They are especially useful in situations where changes to a wiring system are anticipated, since new cables can be installed by laying them in the tray, instead of pulling them through a pipe.

Packing (firestopping)

Packing is the process and/or the materials used in filling both service penetrations and building joints with backer materials as approved components within a firestop.

Fire damper

Fire dampers are passive fire protection products used in heating, ventilation, and air conditioning (HVAC) ducts to prevent the spread of fire inside the ductwork through fire-resistance rated walls and floors. Fire/smoke dampers are similar to fire dampers in fire resistance rating, and also prevent the spread of smoke inside the ducts. When a rise in temperature occurs, the fire damper closes, usually activated by a thermal element which melts at temperatures higher than ambient but low enough to indicate the presence of a fire, allowing springs to close the damper blades. Fire dampers can also close following receipt of an electrical signal from a fire alarm system utilising detectors remote from the damper, indicating the sensing of heat or smoke in the building occupied spaces or in the HVAC duct system.

Bus duct

In electrical power distribution, a bus duct, is a sheet metal duct containing either copper or aluminium busbars for the purpose of conducting a substantial current of electricity. It is an alternative means of conducting electricity to power cables or cable bus.