This section is from the book "The Principles And Practice Of Modern House-Construction", by G. Lister Sutcliffe. Also available from Amazon: How Your House Works: A Visual Guide to Understanding & Maintaining Your Home.
In towns certain precautions against conflagrations are now invariably taken, but in the country, where the chances of extinguishing a fire are much less than in towns, little or nothing is attempted. The upper walls of the country house may be constructed largely of wood, while the same material is used for roofs, floors, windows, doors, skirtings and dadoes, mantel-pieces, partitions, and stairs. From basement to ridge fuel is provided for the flames. Never a winter passes but we read of the destruction by fire of part at least of some historic mansion with treasures of art which cannot be replaced.
The subject of fire-resisting construction is both important and extensive, and only the fringe of it can here be touched. It is a question of materials, and also of their arrangement; for instance, an ordinary floor of wood joists and boards is a most dangerous piece of construction, while a solid wood floor of the same thickness possesses fire-resisting properties of great value.
Materials may be classed as combustible and incombustible. Wood is by far the most important combustible material used in a building, and the less that is used the less will the spread of fire be facilitated. The ordinary studded partitions should give place to walls of brick, or to special fire-resisting partitions. Floors may be of steel and concrete, protected beneath by fire-clay1 or brick. Skirtings and architraves may be of cement. Metal lathing may be used instead of wood laths. Stairs may be of stone or concrete, and in other directions also wood may be superseded by an incombustible material.
The various kinds of wood differ largely, however, in their combustibility. The pines are the most dangerous, and the hard woods the least. A case is on record where an oak post was charred only to a depth of an inch, while a granite column close to it was burnt to powder.
If the combustible materials used in the construction of our buildings are reduced to a minimum, much will have been effected, but care must be taken that the incombustible materials which take their place are at least moderately fire-resisting. The instance just recorded shows clearly that all incombustible materials are not fare-proof. Granite crumbles away under great heat, limestones are nearly as bad, and even the best sandstones are poor in comparison with bricks and terra-cotta. Some concrete, again, is extremely brittle when raised. to a high temperature, while unprotected iron and steel twist and bend. The ordinary lead or composition gas-pipes are a source of danger in fires, as they melt at a comparatively low temperature, and so let loose the inflammable gas upon the burning structure.
Nearly all household tires are caused by the faulty construction of the fireplace or its accessories. I know one room where two fires originated by burning ashes dropping through the joint between the front and back hearths upon the boarded ceiling immediately below; there was no trimmer arch under the hearth or any other protection. Sometimes floor-joists and the purlins of roofs pass directly into chimney-Hues instead of being trimmed OK supported on corbels. The great heat attained in many slow-combustion grates is another source of danger, and before one of these is fixed in an old house the hearth should always be raised, and the construction of the floor and of the hearth-supports be carefully examined. The proper construction of fireplaces and hearths will be more fully discussed in Chapter VI (Broad Irrigation). of this Section.
To prevent the spread of fire from house to house in towns many somewhat stringent regulations are often enforced. The thickness of the party-walls is specified, and every party-wall must be carried through the roof 1 to a height of not less than 15 inches (measured at right angles to the slope of the roof), the thickness of the wall to he not Lan than 8½ inches. In London it is further enacted that "every party-wall shall be carried up of the thickness aforesaid above any turret, dormer, lantern-light, or other erection of combustible materials fixed upon the roof or flat of any building within four feet from such party-wall, and shall extend at the least twelve inches higher and wider than such erection, and every party-wall shall he carried up above any part of any roof opposite thereto, and within four feet thereform".
1See Plate II.
A fire-resisting roof is undoubtedly a great barrier to the progress of a fire, and in towns the flat roof of steel, fire-clay or brick, and concrete, covered with asphalt, is now frequently adopted.
Into the details of fire-extinguishing apparatus it is not proposed to enter, but attention may be drawn to the necessity of providing for large mansions a sufficient store of water for this purpose, with the necessary pipes and hydrants. In smaller houses portable extinguishing apparatus, sometimes known as " chemical fire-engines", will probably suffice; the small hand-grenades may also prove of great service.