Protection from Fire and Thieves / Including the construction of locks, safes, strong-rooms, and fireproof buildings; burglary, and the means of preventing it; fire, its detection, prevention, and extinction; etc.

by George Hayter Chubb

Stone is therefore inadmissible for fireproof purposes, and should not be used for strong-rooms, or as supports for joists or for any part excepting the floor, where it may crack or crumble without affecting the rest of the building. Granite is, as far as experience goes, capable of resisting immense heat; and it is said the great fire at Boston, U.S., in 1873, was stopped when it came to a huge granite warehouse. But the cost of this material and working it are too great for it ever to be extensively used.

Concrete has been lately brought forward as a good, cheap, and fireproof material for making walls and floors, but if used it should be most carefully made; if broken limestone is used it will not be fireproof; but with a mixture of flints, brickbats, sandstone, pebbles, and cement in suitable proportions, a good wall may be erected. One advantage it has over brick is, that being stronger (if plenty of hoop-iron is used as a bond), it occupies less space, and no plastering, or very little, is needed inside.

There has been no case, as far as I am aware, of a large concrete building being subjected to a severe test; therefore, unless other objects were aimed at, I should prefer a brick building. But some warehouses and mills are so large that brick cannot be used internally in arches; and a subdivision by party walls would destroy the business purpose of the building, and allow of only small compartments in it. Cannot iron girders be used in any way to make them safe? To a certain extent they can, if protected over the entire surface by cement or lumps of fire-clay. There should be but few employed, and allowance must be made for the girders, in case they get heated, to expand without thrusting out the walls. They should be supported on corbels of brick, and be as light as possible consistently with the strength required. If used as means to carry a wall they must be covered as suggested, and with the utmost care, for in this case any twisting or bulging sideways will endanger the wall above.

Whatever system of construction is adopted, there are three things not yet mentioned of high importance to the fireproof quality of the building; namely, the communication between the various floors, the style of window, and the construction of the roof. With regard to the first of these, there is little doubt that the ordinary staircase and the open lift are important aids to the spread of fire; by them the various floors of a warehouse are, when combustion begins, converted into so many furnaces with a connecting flue, and the extension of fire is accelerated by the draught rushing upwards. Though the stairs may be uninflammable and even indestructible, they will be in some measure a source of weakness, unless completely separated from the open rooms, as shown in the designs engraved in the Appendix. For these designs of a thoroughly fire-proof warehouse, I am indebted to Mr. E. Hoole, of Russell Square, London; who has succeeded in planning a building adapted to commercial requirements, and yet possessing the necessary elements of a fireproof structure.

All openings must be fitted with double iron doors if perfect security is required, but with a single door if only ordinary risk is to be guarded against. The construction and fixing of these doors are a most important matter, and should be quite as carefully attended to as if the doorway were to a strong-room. Details of fixing them will be found in the chapter on strong-rooms, and the strength of doors should be the same as there shown. The outer plate of door being a half-inch solid boiler-plate, there must be an air-space behind it, partly occupied by the working parts of the lock, and inside that a casing of non-conducting material. The bolts should be six in number, three in front and three at the back, secured by a lock; and the frame into which they fasten must be solid iron, well built into the wall. The price of such a door, 6 feet high by 2 feet 4 inches wide, is 22l. 10s., and money thus spent would many a time have saved thousands in property.

The Building Act can be complied with by providing a sheet-iron door with a plain barrel-bolt, such a division forming no security whatever, as the iron immediately warps, and allows flame or heat to pass through the opening. In this particular the Act has done much harm, for a false sense of security has been felt when its provisions have been met, and money has been wasted in buying, and labour constantly lost in closing and opening doors that are unable to hinder fire from spreading and ensure safety. Cast-iron hinges are sometimes used for these doors, giving another element of danger. Not long since I saw the ruins of a building which had been divided in its various blocks by such doors. Most of the doors were down in the rubbish, while the openings where they had been high up on the walls had the broken hinges left in the brickwork.

No regulations for fireproof building can be complete without most stringent rules for using the best fire resisting doors, for what the door of a boiler-furnace is to the fire within, the door of a room is to combustion going on inside: it will, if insecure, allow air in to feed the flames so long as there is fuel to burn.

But there are other openings necessary to warehouses; and this leads to the subject of the windows, which are in the fireproof sense a necessary evil. The danger consists in the draught which comes through to feed the fire; but the risk can be lessened by using very thick glass, in small squares, and taking care that no broken panes are allowed to remain in the windows. If anyone takes the trouble to notice such a thing, he will scarcely find a warehouse without some broken squares, which will admit air enough to fan a fire to the temperature of a blast-furnace in a very short time.

Iron sashes should be used; and iron shutters may be also used to cover the windows, capable of being opened easily on the outside by firemen if required. Capt. Shaw states that heavy losses have been caused through the firemen being unable to open iron shutters from the outside, in consequence of their expansion from heat. He also gives a warning against the too common practice in cheap buildings of using glass with bullseyes or dents, through which the rays of the sun become concentrated and set fire, as has been the case, to the interior. Projecting or bow-windows must not be adopted, as fire can more easily pass in this way from one opening to another.

The remaining particular to be noticed is the construction of the roof, by the falling in of which the destruction commenced below it is so often completed. The high Mansard roofs appear to have largely contributed to the destruction of Chicago and other American cities. It is somewhat alarming to see the extent to which they are being employed in England; but whatever form of roof is used, the materials of which the framing is composed should be incombustible, and the ceiling beneath it ought to be perfectly fireproof, so that fire beneath cannot ascend to the roof, or descend from the roof to the rooms. A fireproof ceiling is also valuable for preventing the building being deluged with water from the engines, when fire has attacked the roof only. If any openings to the roof are necessary, they must be constructed with care and placed in a room—not at the top of a staircase, as is so frequently done, where the draught of air is likely to be concentrated.