New Edition of N.B.F.U. Building Code
The National Board of Fire Underwriters, 85 John St., New York 38, N. Y., recently announced the publication of the Golden Anniversary Edition of its Recommended National Building Code.
Revised many times since it first appeared in 1905, and completely so for the 1955 Golden Anniversary Edition, the code provides authoritative answers to a number of questions of wide current interest in the field of building design. For instance:
When is it proper to use glass and other light noncombustible panel walls in exteriors of buildings?
How should exceptionally large industrial buildings be constructed for reasonable fire safety?
The new code, according to the National Board, handles exterior building waffs thus:
It makes their required fire resistance dependent on the amount of permanent open space between them and the nearest line to which a building is built or may legally be built. For exterior walls on a property line, a fire resistance of three hours is required and the total area of windows in such walls is restricted. As the distance from the lot line is increased, the fire resistance is lessened and the amount of permitted window area increased until a separation distance of 30 feet is reached. In which case, with certain exceptions, the walls may be without fire resistance rating, thus permitting them to be made entirely of glass or other noncombustible material.
For industrial buildings of exceptionally large area a separation of at least 80 feet is required from lot lines and construction is limited to that which is noncombustible. Sprinklers are required except for an occupancy which uses nothing but noncombustible materials.
Another problem of special interest in many parts of the country, and one on which the code gives newly-revised and expanded information, is how to construct buildings so as to minimize windstorm damage. This is handled by an appendix giving detailed suggestions on roof anchorage, attachment of roof coverings and other features of design.
Still another problem of wide current interest is: How may plastics be properly used in building construction?
The new code, in making provision for their use—with special provisions covering use in windows and skylights, and light-diffusing ceilings—relates their use to basic requirements on combustibility and flamespread characteristics as applied to other building materials and takes advantage of special conditions in which plastics may be used with little fire hazard.
The new code also allows larger increases in areas of buildings for installation of automatic sprinklers than have been recognized in previous editions of the code or in other building codes. These larger areas for sprinklered buildings were arrived at on the basis of the knowledge and experience of fire underwriters in evaluating the worth of automatic sprinkler systems.
Emphasis is placed on the fact that the National Building Code is a performance code and insofar as practicable, within the limits of public safety, allows for the use of any material, type of assembly, method of construction, or style of architecture that meets the required standards of strength, stability and fire resistance.
The National Building Code contains 16 appendices giving supplementary information.
One of the appendices most widely used contains a code covering the installation of heat producing appliances of all types, including air conditioning, blower and exhaust systems.
Another appendix contains a tabulation of fire-resistance ratings of walls, floors and other building parts. The tabulation is the most complete and up-to-date compilation of data of this type available. It may be used with any other modem code as all such codes contain requirements in terms of fire resistance rating.