FIRE AND SMOKE BARRIERS DESIGN IN CIVIL BUILDING CONSTRUCTION BASICS AND TUTORIALS

FIRE AND SMOKE BARRIERS DESIGN IN CIVIL BUILDING CONSTRUCTION 
What Are The Fire And Smoke Barriers In Building Construction?


A major consideration in building design is safety of the community. Hence, buildings should be designed to control fires and smoke so that they will not spread from building to building. One way that building codes try to achieve this objective is to establish fire zones or fire limits that restrict types of construction or occupancy that can be used.

Additional zoning regulations establish minimum distances between buildings. Another way to achieve the objective is to specify the types of construction that can be used for enclosing the exterior of buildings.

The distance between adjoining buildings, fire rating, and stability when exposed to fire of exterior walls, windows, and doors, and percent of window area are some of the factors taken into account in building codes for determination of the construction classification of a building.

To prevent spread of fire from roof to roof, building codes also often require that exterior walls extend as a parapet at least 3 ft above the roof level. Parapets also are useful in shielding fire fighters who may be hosing a fire from roofs of buildings adjoining the one on fire. In addition, buildings should be topped with roof coverings that are fire-resistant.

Fire Divisions.
To prevent spread of fire vertically in building interiors, building codes generally require that floor-ceiling and roof-ceiling assemblies be fireresistant. The fire rating of such assemblies is one of the factors considered in determination of the construction classification of a building.

Also, openings in floors and roofs should be fire-protected, although building codes do not usually require this for one-story or two-story dwellings. For the purpose, an opening, such as that for a stairway, may be protected with a fire-resistant enclosure and fire doors.

In particular, stairways and escalator and elevator shafts should be enclosed, not only to prevent spread of fire and smoke but also to provide a protected means of egress from the building for occupants and of approach to the fire source by fire fighters.

To prevent spread of fire and smoke horizontally in building interiors, it is desirable to partition interiors with fire divisions. A fire division is any construction with the fire-resistance rating and structural stability under fire conditions required for the type of occupancy and construction of the building to bar the spread of fire between adjoining buildings or between parts of the same building on opposite sides of the division. A fire division may be an exterior wall, fire window, fire door, fire wall, ceiling, or firestop.

A fire wall should be built of incombustible material, have a fire rating of at least 4 hr, and extend continuously from foundations to roof. Also, the wall should have sufficient structural stability in a fire to allow collapse of construction on either side without the wall collapsing. Building codes restrict the size of openings that may be provided in a fire wall and require the openings to be fire-protected (Art. 11.55).

To prevent spread of fire through hollow spaces, such spaces should be firestopped. A firestop is a solid or compact, tight closure set in a hollow, concealed space in a building to retard spread of flames, smoke, or hot gases.

All partitions and walls should be firestopped at every floor level, at the top-story ceiling level, and at the level of support for roofs. Also, very large unoccupied attics should be subdivided by firestops into areas of 3000 ft2 or less.

Similarly, any large concealed space between a ceiling and floor or roof should be subdivided. For the purpose, firestops extending the full depth of the space should be placed along the line of supports of structural members and elsewhere, if necessary, to enclose areas not exceeding 1000 ft2 when situated between a floor and ceiling or 3000 ft2 when located between a ceiling and roof.

Openings between floors for pipes, ducts, wiring, and other services should be sealed with the equal of positive firestops. Partitions between each floor and a suspended ceiling above are not generally required to be extended to the slab above unless this is necessary for required compartmentation. But smoke stops should be provided at reasonable intervals to prevent passage of smoke to noninvolved areas.

FIRE PROTECTION CONCEPT OF BUILDINGS BASICS AND TUTORIALS

FIRE PROTECTION CONCEPT OF BUILDINGS BASIC INFORMATION
Importance Of Building Fire Protection


Although fires in buildings can be avoided, they nevertheless occur. Some of the reasons for this are human error, arson, faulty electrical equipment, poor maintenance of heating equipment, and natural causes, such as lightning.

Consequently, buildings should be designed to minimize the probability of a fire and to protect life and limit property damage if a fire should occur. The minimum steps that should be taken for the purpose are as follows:

1. Limit potential fire loads, with respect to both combustibility and ability to generate smoke and toxic gases.

2. Provide means for prompt detection of fires, with warnings to occupants who may be affected and notification of the presence of fire to fire fighters.

3. Communication of instructions to occupants as to procedures to adopt for safety, such as to staying in place, proceeding to a designated refuge area, or evacuating the building.

4. Provide means for early extinguishment of any fire that may occur, primarily by automatic sprinklers but also by trained fire fighters.

5. Make available also for fire fighting an adequate water supply, appropriate chemicals, adequate-size piping, conveniently located valves on the piping, hoses, pumps, and other equipment necessary.

6. Prevent spread of fire from building to building, either through adequate separation or by enclosure of the building with incombustible materials.

7. Partition the interior of the building with fire barriers, or divisions, to confine a fire to a limited space.

8. Enclose with protective materials structural components that may be damaged by fire (fireproofing).

9. Provide refuge areas for occupants and safe evacuation routes to outdoors.

10. Provide means for removal of heat and smoke from the building as rapidly as possible without exposing occupants to these hazards, with the air-conditioning system, if one is present, assisting the removal by venting the building and by pressurizing smokeproof towers, elevator shafts, and other exits.

11. For large buildings, install standby equipment for operation in emergencies of electrical systems and elevators.

FIRE PROTECTION STANDARDS FOR BUILDING CONSTRUCTION PROJECTS BASIC AND TUTORIALS

FIRE PROTECTION STANDARDS FOR BUILDING CONSTRUCTION PROJECTS
What Are The Fire Protection Standards For Buildings?


The standards most widely adopted are those published by the National Fire Protection Association (NFPA), Batterymarch Park, Quincy, MA 02269. The NFPA ‘‘National Fire Codes’’ comprise several volumes containing numerous standards, updated annually. (These are also available separately.)

The standards are supplemented by the NFPA ‘‘Fire Protection Handbook,’’ which contains comprehensive and detailed discussion of fire problems and much valuable statistical and engineering data.

Underwriters Laboratories, Inc. (UL), 333 Pfingsten Road, Northbrook, IL 60062, publishes testing laboratory approvals of devices and systems in its ‘‘Fire Protection Equipment List,’’ updated annually and by bimonthly supplements.

The publication outlines the tests that devices and systems must pass to be listed. The UL ‘‘Building Materials List’’ describes and lists building materials, ceiling-floor assemblies, wall and partition assemblies, beam and column protection, interior finish materials, and other pertinent data.

UL also publishes lists of ‘‘Accident Equipment,’’ ‘‘Electrical Equipment,’’ ‘‘Electrical Construction Materials,’’ ‘‘Hazardous Location Equipment,’’ ‘‘Gas and Oil Equipment,’’ and others. Separate standards for application to properties insured by the Factory Mutual System are published by the Factory Mutual Engineering Corporation (FM), Norwood, MA 02062. FM also publishes a list of devices and systems it has tested and approved.

The General Services Administration, acting for the federal government, has developed many requirements that must be considered, if applicable. Also, the federal government encourages cities to adopt some uniform code.

In addition, buildings must comply with provisions of the Americans with Disability Act (ADA). (See Department of Justice final rules, Federal Register, 28 CFR Part 36, July 26, 1991; American National Standards Institute ‘‘Accessibility Standard,’’ ANSI A117.1; ‘‘ADA Compliance Guidebook,’’ Building Owners and Managers Association International, 1201 New York Ave., Washington, D.C. 20005.)

The Federal Occupational Safety and Health Act (OSHA) sets standards for protecting the health and safety of nearly all employees. It is not necessary that a business be engaged in interstate commerce for the law to apply. OSHA defines employer as ‘‘a person engaged in a business affecting commerce who has employees, but does not include the United States or any State or political subdivision of a State.’’

An employer is required to ‘‘furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees.’’ Employers are also required to ‘‘comply with occupational safety and health standards promulgated under the Act.’’

Building codes consist of a set of rules aimed at providing reasonable safety to the community, to occupants of buildings, and to the buildings themselves. The codes may adopt the standards mentioned previously and other standards concerned with fire protection by reference or adapt them to the specific requirements of the community.

In the absence of a municipal or state building code, designers may apply the provisions of the Uniform Building Code, promulgated by the International Conference of Building Officials, or other national model code.

Many states have codes for safety to life in commercial and industrial buildings, administered by the Department of Labor, the State Fire Marshal’s Office, the State Education Department, or the Health Department. Some of these requirements are drastic and must always be considered.

Obtaining optimum protection for life and property can require consultation with the owner’s insurance carrier, municipal officials, and the fire department. If the situation is complicated enough, it can require consultation with a specialist in all phases of fire protection and prevention.

In theory, municipal building codes are designed for life safety and for protection of the public, whereas insurance-oriented codes (except for NFPA 101, ‘‘Life Safety Code’’) are designed to minimize property fire loss.

Since about 70% of any building code is concerned with fire protection, there are many circumstances that can best be resolved by a fire protection consultant.