BUILT-IN
PROTECTION
Steel is generally regarded as a fire renating material of the highest order, yet this photograph takes after the fire at the premises of the Hongkong & Kowloon Wharf & Godown Company, illustrates what fire can do to unprotected steel (Photograph by Gainsborough Studio,.
It is not generally realized that the term "fire-proof construction" as applied to domestic and office buildings, and particularly to factories and godowne, implies not only the use of incombustible materials in their construction, but also their correct application in the design. As a particular instance, we might mention that the walls must not only be built of fire resisting materials, but they must be of a particular thickness and must be recessed into the columns in accordance with certain definite regulations appertaining thereto.
Complete rules governing fire resisting construction in every type of building are published by the Fire Protection Association, and strict compliance with these rules will enable the owner of a building to obtain substantial reductions in fire insurance premiums. These rules must be incorporated into the building specifications before construction work starts as it may be impossible, or at any rate uneconomical, to attempt to effect the necessary alterations once the building is com- pleted. It is, therefore, important that architects and owners consult these rules during the early planning stages.
When planning the construction of commercial and industrial buildings, particularly Godowns and Factories, also Theatres and Cinemas, the saving in insurance premiums which can be obtained by building in accordance with the Insurance Offices' Rules for Fire Resisting Construction should be remembered.
Any Architect or Insurance Company can furnish informa- tion as to the Rules and of the reductions in premiums, and it is a simple matter for the Architect to figure out the extra cost, if any, of building to the specifications laid down.
The Fire Offices Committee in England maintain, jointly with the Department of Scientific and industrial Research, a fully equipped Testing Station at Elstree where, not only are tests of various building and constructional materials made, but careful records are kept of the behaviour of various types of buildings which have been exposed to actual fires.
The Rules are the result of these tests and of experience by the Fire Offices and their expert advisers. They provide the minimum requirements under which allowances can be granted and all rules must be given effect to in the plans and specifications. It may be much more costly, or even impossible, to make alterations to comply with the Rules once construction has commenced, so that care should be taken that they are considered in the preliminary planning.
The only Rules in which some latitude is allowed are those relating to maximum height, which is 100 feet for Office and Factory buildings and 80 feet for Godowns. Some addi- fional height may be allowed subject to additional fire protec- tion and fire fighting appliances being available. If extra height is planned, the Architect and Insurance Company should be consulted beforehand to ascertain what special requirements are needed.
con-
The point to remember is that the building is structed so as to strictly conform with the Rules, a reduction in insurance premiums can be obtained up to 20'; depending upon the standard of construction applicable, both on the building and on contents. This is particularly important in the case of godowns and factories, where very valuable stocks of goods or machinery may have to be insured in addition to the building itself.
In buildings where different processes are carried on or different types of goods are stored, a particularly large saving can be made by complying with the Rules for separation of compartments or adjoining buildings, which may save the exposure of non-hazardous parts of the structure from risk of fire from parts where there is a higher fire hazard. Not only may this result in a saving of a high rate of premium over a large part of the building but, in case fire does occur, may confine it to a small part of the risk.
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The following are extracts from the Rules applicable to office buildings and to buildings of the domestic class not wholly of reinforced concrete construction. We wish to emphasize that they are quoted merely as an indication of what are contained in these ruler. The Fire Insurance Association of Hongkong will be glad to furnish the complete regulations and to advise
any points which require clarification.
Rule 1.
Height
on
Height shall not exceed 100 feet, measured from the lowest point of the land level or ground line of the site on which the building stands to the level of the highest part of the roof.
Rule 2. Compartments and communications
A compartment in a building of the domestic class Standard A construction must be separated from any adjoining building by a party wall and must not communicate therewith otherwise than through a fireproof lobby except as follows:- (a) through openings fitted with double fireproof doors if both buildings are of the domestic class Standard A construc- tion.
(b) through openings fitted with double fireproof doors if the communicating building is of the godown class Standard C construction and the combined cubical capacity of the communicating compartments does not exceed 130,000 feet. Rule 4. Walls, Piers, Columns and Stanchions
Every party wall must be at least 13 inches thick in every The part, and comply in all respects with Definition (c). party wall must be carried up at least 3 feet above the roof of the building of Standard A construction, unless the adjoin- ing building is itself of Standard A or C construction in which case the party wall need not be carried through the roof, provided there be no openings in either roof within 10 feet of the party wall.
Rule 5.
Every division wall must be at least 8 inches thick in every part, and must comply in all respects with Definition (d).
Rule 7.
Every external wall and area wall must be at least 13 inches thick in every part, except as regards curtain walls constructed as panels of not more than 300 feet of superficial area including openings therein, such panels being supported by a framework of steel or reinforced concrete, in which case the panels need not be more than 8 inches thick exclusive of the facing.
N.B. In order to receive curtain wall panels, the columns abutting thereon shall be provided with grooves having a depth of at least 1 inch and a width of at least 5 inches.
Rule 9. Openings in External and Area Walls
Under certain conditions every window or other opening above the ground storey... shall be protected by Areproof shutters or fireproof doors or be glazed with wired glass or electro copper glazing.
Rule 10 (a). Floors
Floors if solid shall be constructed of brick, terra-cotta, fire clay and/or concrete at least 5 inches thick devoid of cavity.
Rule 10 (b).
If hollow-shall be constructed of hollow blocks and concrete at least 6 inches thick, the total thickness of solid material being at all points at least 4 inches of which at least 2 inches must be concrete forming the top of the blocks (which must be well grouted in cement) or concrete above the highest point of the blocks. The hollow blocks must have top and bottom and sides composed of the materials named in (a) above, at least 2 inch thick.