HOUSE REFUSE.
In an ordinary household the disposal of ashes from fires, of broken pots and cans, of waste-paper, and of vegetable and animal debris form a serious difficulty. The difficulty is one that can be minimised by the careful housekeeper. Old newspapers, etc., may be sold, though their value is very small; other waste-paper should be burnt. All vegetable and animal debris should be burnt. This may be effected without nuisance if coal-fires are in use, by placing potato-peelings, cabbage leaves and similar substances under the fire until thoroughly dried, and then burning them. The careful housewife will not waste bones, but utilise them for soup. After being boiled they are much less liable to putrefy in the dust-bin; but should even now be burnt in the fire. If this plan be pursued, the contents of the dust-bin will be simply ashes, broken pots and cans, and a few cinders—here again a sifter is desirable—and no nuisance can arise. It is only organic refuse that smells. If only gas or paraffin stoves are in use, as during the summer months, any possible nuisance in connection with the dust-bin is minimised by allowing all refuse to dry before it is placed in the dust-bin, or by wrapping all putrefiable substance inside several layers of newspaper.
In emptying the dust-bin or ash pit, care must be taken that the bottom is thoroughly scraped out. It is well to keep some quicklime (thoroughly dry) for sprinkling on the bottom and sides of the receptacle each time after it is emptied. This greatly helps in keeping it dry and diminishing nuisance during summer.
In many households a separate receptacle is kept for what is known as “hog-wash,” containing waste-food, often in a foul and putrefying condition. In well-ordered households, except in hotels and similar establishments, there is no necessity for a “hog-wash” tub, and its presence argues wastefulness and carelessness. Food which cannot be eaten because it has “gone bad” should be burnt.
Two forms of receptacle are used for house-refuse, an ash-pit or a dust-bin. An ash-pit is a fixed receptacle for the reception of house-refuse. In many towns the same receptacle is used for excreta. Then we have a privy or privy midden, according to size (see page [196]). Ash-pits for household refuse alone should be small, so as not to hold more than a week’s refuse. No part should be below the ground level. The floor and walls should be lined with impervious smooth cement, and the ash-pit should have a hinged cover to keep out rain, and a door on one side to facilitate emptying. The ash-pit should be at least six feet distant from any wall of the house. Even the best constructed ash-pit is as much worse than a dust-bin, as a privy is worse than a pail closet. A fixed is always less easily cleansed than a movable receptacle.
A dust-bin is usually made of galvanized iron with a tight-fitting lid. This receptacle can be kept clean, and can be carried without any transference to another tub direct to the cart.
The removal of house refuse constitutes an important part of municipal work. In most towns it is carried out weekly, sometimes less frequently, while in some towns removal twice or three times a week is secured. A daily removal is carried out in a few towns, and this is by far the best plan, as decomposition and the dangers associated with it have then no chance of becoming serious. The house refuse should always be conveyed through the streets in covered carts.
The disposal of house refuse constitutes a problem of increasing difficulty. Unfortunately in the suburbs of many towns it is deposited on low-lying land in disused quarries and brickfields. When land has been thus levelled, it often next appears as “an eligible building site.” A very common practice has been to excavate gravel and sand upon the site of proposed dwellings, and allow the excavation to be filled with dust-bin refuse. Before building on such a soil it is necessary to excavate down to the virgin earth, and to render it impervious by a layer of cement concrete.
A second method is to sift and sort the refuse, separating by means of sieves the finer ash and dust from the coarser parts. This is usually carried out in a large dust-yard adjoining a river or railway-siding. The “breeze,” consisting of cinders and coals, along with the fine ash, are sold to brickmakers; the “hard core,” consisting of clinkers, broken crockery, etc., is used for road making; and the “soft core,” consisting of animal and vegetable refuse, to which is often added stable manure, is sold for manure. Iron, tin, paper, rags, bottles, and corks are separately collected and sold. This disgusting process, often carried on by women, is now gradually being disused.
A third method is to cremate the house refuse. This has been done to a large extent by burning the house refuse for making bricks (page [124]). This method of slow and imperfect combustion necessarily involves a nuisance. A more elaborate means of securing the same end is by the modern Destructor, which has been gradually brought towards perfection. A destructor is a large furnace, in which, after the fire has been first lit, the combustible matter in the house refuse suffices to keep it alight. Various mechanical devices are in use for emptying the trucks of house refuse on to the fires without handling it, for clearing out of the fire the inorganic refuse, and for ensuring sufficiency of draught. The amount of draught has in the older destructors been dependent upon the height of the chimney. In some more recent destructors the same end has been more efficiently secured by injecting a steam blast into the furnaces. A temperature of about 2,000° F. is reached in certain parts of the destructor, the rapid draught ensuring enormous heat. In view of the possibility of a portion of the smoke not being completely burnt, a second “fume cremator” is often provided, through which the products of combustion in the furnace are passed. The fuel in the “fume cremator” is coke. Besides incomplete combustion of combustible material, which is rare when the fume cremator is provided, the escape of fine dust up the chimney requires to be guarded against. This is partially prevented by ledges near the bottom of the chimney. In a destructor the house refuse is reduced to about one-third of its original bulk, the residue being innocuous clinker, metallic refuse, and dust. This material can be utilised for making roads, and in the manufacture of mortar. The waste heat of the destructor has been partially utilised for various purposes. This method of disposal of house refuse is usually the best available for large towns, and offers the additional advantage that no nuisance is caused by the deposit of offensive material in neighbouring districts.
[CHAPTER XXX.]
POSITION OF THE HOUSE.
Lord Bacon said: He who builds a fair house upon an ill seat committeth himself to prison.” The first considerations, therefore, in choosing a house are those of aspect, surrounding objects, and soil. On the first of these considerations, that of aspect, Thomas Fuller’s quaint remarks give the essential points. He says:
“Light (God’s eldest daughter) is a principal beauty in a building; yet it shines not alike from all parts of heaven. An east window welcomes the beams of the sun before they are of strength to do any harm, and is offensive to none but a sluggard. A south window in summer is a chimney with a fire in it, and needs the screen of a curtain. In a west window in summer towards night the sun grows low and even familiar, with more light than delight. A north window is best for butteries and cellars, where the beer will not be sour from the sun shining on it.”
A workroom or study requiring steady light, should point north or some point between north-east and north-west. A breakfast room should face north-east to south; while one aspect of a drawing-room should be south-east to north-east. Store-rooms, dairies, larders, should have a northerly aspect. It is preferable, as a rule, for the house not to face in the direction of the four points of the compass, but diagonally to these.
Surrounding Objects of an objectionable character, as factories, noisy or offensive trades are to be avoided. The possibility of neighbouring cesspools contaminating the water supply must be considered. Trees close to a house are objectionable, rendering it damp, and preventing the free access of sun and air. More remote from the house they form a useful shelter, especially when to the north or east.
The banks of water courses are to be avoided for similar reasons. If there is a choice, the slope of a hill should be selected; and it is essential that no part of the dwelling should rest against sloping ground at a higher level. Rank vegetation indicates a damp clayey soil.
The main point is to secure that the house shall receive ample light and ventilation. In calculating the amount and intensity of sunshine which a house built on a given site will secure the variations according to season must be remembered. The direction (orientation) of the sun is the same all the year through; but the altitude of the sun varies with the latitude. Thus in a house facing directly south in the latitude of the south of England the sun’s altitude at noon on the 21st of December is 15° 4´, on the 21st of June 62° 4´. A ray of light entering the highest point of a window facing south at each of these seasons will illuminate a much larger part of the room in summer than in winter. Not only so, but inasmuch as it enters the room more nearly vertically it is more powerful than when entering at an angle more nearly approximating a horizontal direction, in accordance with the general law that the intensity of illumination falling on a horizontal surface (as the floor of a room) is inversely as the square of the width of the area embraced within the same angle of incidence of light.
In houses in a street the angular aperture through which light enters is greatest in the upper stories. It may be increased (a) by increasing the height of rooms; (b) by carrying the window heads nearly to the level of the ceiling; and (c) by avoiding the proximity of other buildings which would impede the access of light. Fig. 36 shows the importance of the last consideration. This represents a three-storied house in a street, of which the opposite house L is of the same height. It will be observed that each room is divided into two regions of different degrees of illumination by a plane Lm, formed by a line connecting the ridge of the roofs of the houses on the opposite side of the street with the interior surface of the rooms and touching the uppermost point of the window in transit. Below this line there is “sky-light” sufficient in quantity; above this line light is insufficient in amount and is diffused and reflected. The area receiving sufficient light increases from the ground floor upwards. We have already seen that its intensity similarly increases in the higher stories, the rays of light being more nearly vertical in these.
Fig. 36.
Showing Variations of Illumination in Different Stories.
The amount of sky-light visible can be expressed in terms of the angle of aperture, i.e. the arc of sky visible at any given point a in the room. Thus in Fig. 36 the triangle of aperture bac is greater than b´a´c´, and this greater than b´´a´´c´´. The sides of the angle of aperture, it will be seen, are formed by drawing one line from the point a to c, which, if prolonged, would touch L, and another line to b, which passes through the highest point of the window.
The amount of light received in a dwelling-house is largely determined by the width of the street and the distance between the backs of the houses in adjacent streets. The model Bye-laws of the Local Government Board insist that no new street shall be less than 36 feet wide if it exceeds 100 yards in length or is intended to be a carriage road, not less than 24 feet in any case. Furthermore, a new house must have in the rear an open space exclusively belonging to the house, at least 150 square feet in area, and free from any erection above the ground level. This must extend along the entire width of the house, and must never measure less than 10 feet from every part of the back wall of the house; the distance must be at least 15 feet, if the house is 15 feet high; 20 feet if 25 feet high, and 25 feet if 35 feet high or more.
Fig. 37.
Diagram Illustrating the Necessary Requirements as to Open Space in Front of and at the Rear of Dwelling-houses.
Streets should never be less in width than the height of the houses in them; and a line drawn from the ridge of the roof to the foot of the wall of the opposite houses (Fig. 37) or in the rear to the foot of the wall or fence dividing the back yards of contiguous houses, should not make an angle of more than 45º with the ground (Fig. 37). This is the angle required for new buildings in the residential parts of Liverpool, and was proposed for London, but unfortunately not made obligatory. The size of windows is discussed on page [216]. The light received in a given house is often diminished at corners of streets by contiguous houses.
The Soil has an important influence on the healthiness of a site. The relative merits of the different kinds of soil are discussed on page [219]. Undrained soils of whatever kind are bad, and made-soils are always to be regarded with profound distrust.
The planning of a house should be carefully considered. The principle is that the sun should enter every living room at some time of the day. The relative positions of fire-place, window, and door in each room are important. With the sole window of a room in the same wall as the fire-place the area ventilated is the least, with it situated on the opposite wall the area ventilated is the greatest. The door should be as remote from the window as possible, in order to secure occasional perflation of air; the two being preferably on opposite walls. Staircase windows are indispensable to secure through ventilation of a dwelling. Houses constructed “back to back” cannot be properly ventilated as no through current of air is possible. Hence the necessity for open yards at the area, as well as air-space in front of the house. (Fig. 37).
In the construction of a house, apart from access of light and air, the main problems are to secure dryness and equability of temperature. We shall consider in this connection the materials used in the construction of walls, floors, and roofs.
[CHAPTER XXXI.]
THE MATERIALS USED IN THE CONSTRUCTION OF A HOUSE.
In this country walls of houses are usually built of brick, stone, timber, or concrete, of which the first two are the most important. Timber is, owing to its inflammability, only allowed to be used in towns under special restrictions. Bricks and stones are bonded together and imbedded in mortar or cement.
There are several kinds of bonds in brickwork, of which the strongest is the English. This consists of alternate courses of “headers” and “stretchers,” the former being bricks carried through the wall from face to back, the short end showing on the face, and the latter bricks laid lengthwise along the face of the wall. Hence the wall is held together in every direction. A Flemish bond consists of alternate headers and stretchers in the same course. It is used where a specially smooth wall is desired, but is not so strong as the English bond.
Bricks are generally of a uniform size, of 9 inches in length by 4½ in width and 2¾ inches in thickness. Those bricks which are heaviest and hardest are generally the most durable; bricks of good quality when knocked together give a clear ringing sound.
The relative conductivity for heat of brick as compared with other materials, is shown in the following table, from Galton, which gives the units of heat transmitted per square foot per hour by a plate 1 inch thick, the two surfaces differing in temperature 1° Fahr.:—
| Stone—ordinary free stone | 13·68 |
| Glass | 6·6 |
| Brickwork | 4·83 |
| Plaster | 3·86 |
| Fir planks | 1·37 |
| Brick dust | 1·33 |
It is evident that in this respect, brick walls compare very favourably with stone walls, and are much more economical of heat. Increased conductivity of a material may be counteracted by increased thickness.
Brick is very porous, as shewn by its power to absorb moisture. A good brick can absorb from 10 to 20 per cent. of its weight of water; while good granite only takes up ½ per cent., sandstone usually from 8 to 10 per cent., marble only a trace, and Portland limestone 13½ per cent.
Being porous, brick allows the passage of a considerable amount of air, unless its pores are occupied by moisture. The following table, from Galton, shews the number of cubic feet of air which every hour pass through a square yard of wall-surface of equal thicknesses, built of the following materials, there being a temperature of 72° Fahr. on one side the wall, and of 40° on the other:—
| Wall built of | brick | 7·9 | cubic feet. |
| „ | quarried limestone | 6·5 | „ |
| „ | sandstone | 4·7 | „ |
| „ | limestone | 10·1 | „ |
| „ | mud | 14·4 | „ |
Mortar should consist of clean sharp sand and slaked lime, usually in the proportion of three of the former to one of the latter. Grouting, or liquid mortar, is merely ordinary mortar to which a larger quantity of water has been added. It is used for filling up the crevices between the brickwork about every fourth course, and is required to a greater extent in stone work, owing to the difficulty in filling up spaces left by inequalities in the stone.
The sand used in mortar should be free from small stones. It should not contain any earthy or clayey matters, as these greatly diminish the adhesive quality of the mortar, which depends on the combination of the sand and lime. All the sand used in a building should be washed, unless it is perfectly clean, in order to remove impurities. Many builders use an inferior mortar, in which other materials, such as “road scrapings,” are substituted for sand. Sand taken from the sea-shore is unfit for making mortar, as the salt contained in it is apt to deliquesce and weaken the mortar.
Lime is obtained by burning chalk or limestone in a kiln. Thus CaCO₃ = CaO + CO₂. There are three kinds of lime: (1) Fat or quicklime, used for internal plastering, (2) stone lime, used for ordinary building work, and (3) hydraulic lime, used for building in damp situations. The last named contains a quantity of silicates, and sets under water.
Common mortar crumbles away, if laid under water before it has had time to harden.
Portland cement is an artificial cement, of a dark grey colour. It is made by grinding chalk, mixing it with blue clay or river-mud in certain proportions, and then burning it in a kiln and afterwards grinding it to a fine powder. It is used, mixed with sand, for external plastering (“compoing”) of walls, for making concrete, or instead of lime for making mortar if extra strength is required.
Compo consists of Portland cement and sand, and is used for covering walls when an impervious smooth surface is required, and for keeping out rain. It is laid on in two coats. The first or rough coat ¾ inch thick, is composed of one part cement to 5 parts compo sand, i.e. coarse sand mixed with fine beach. The outer or fine coat is composed of two parts fine or washed sand to one part cement. To “render” or “compo” a wall is to cover it with this material. The internal plastering of a chimney flue is called “pargetting.”
Concrete is of two kinds, lime or cement concrete. It is composed of three parts broken ballast or large beach, two parts of sand, and one part of lime or cement. Lime concrete has no resisting strength, and is only used for surrounding drain-pipes, or where no great strength is required.
Stone varies very greatly in character. It is uncommon for the whole thickness of the walls of a house to be built of stone; usually there is merely a facing of stone and a backing of brickwork. If good stone is not available, the less it is used the better.
The stone chosen should be durable, and able to resist the action of the sulphuric, sulphurous, and carbonic acids absorbed from the atmosphere, and brought in contact with it by means of rain. The stone of which a considerable part of the Houses of Parliament consists is dolomite, a double carbonate of lime and magnesia. The acid fumes in the air produce on its surface sulphate of magnesium, which is washed away in successive layers.
If the stone presents any stratification, it should be laid in the wall in the same position as that in which it was originally deposited in the quarry. Thus, any planes of stratification will be horizontal, and the scaling off by the action of frost and rain is minimised. Comparatively homogeneous stones, such as granite and millstone-grit, can be laid in any position. In testing the character of any stone, the least porous, densest, and most resistent to crushing, will as a rule be the most durable.
The chief difficulty in the use of stone for the walls of houses, is that of keeping out the wet. To obviate this, stone-houses are often built of great thickness, and are consequently cooler in summer and warmer in winter.
In and near large towns brick is chiefly used for walls of houses, and stone employed only for window-sills, columns, steps, etc. It is even more important in these cases to carefully select the stone, as the parts where it is placed are those most exposed to the weather. If a soft, friable freestone is used, after a sharp frost large scales are seen falling off in flakes, owing to the freezing and subsequent thawing of the moisture in the stone.
Portland stone is the best-wearing stone to be had in the neighbourhood of London. Bath stone is also considerably used, but it varies greatly in quality, and should be very carefully selected. For landing-steps and paving, Yorkshire stone is extensively used, but artificial cement pavings are replacing it to some extent. Most kinds of stone can only be economically used near the quarries from which they are derived.
The Slate used for roofs is an altered form of clay, possessing a laminated structure. The ease with which it splits along the planes, renders it peculiarly suitable for this purpose. The Welsh slates are considered the best.
Terra-cotta is made from certain kinds of clay, mixed with glass, pottery or sand; then ground up, strained, and kneaded; and lastly thrown into moulds and baked in a kiln.
Iron and Wood have occasionally been employed alone in building houses. The former, owing to its good conducting powers for heat, is cold in winter and hot in summer; while the latter becomes rotten from exposure to wet, and is also very combustible. Corrugated iron buildings lined with wood are also employed, but are not very satisfactory.
For roofs, slates or tiles are the materials most frequently employed; but occasionally lead and corrugated iron are used, also thatch in country places, and tarred felt for temporary buildings.
Lead is the most suitable metallic covering for roofs, as it is durable and easily worked. It is, however, heavy and demands considerable strength in the timbers by which it is supported. Galvanized iron has also been largely used. It is cheaper and lighter than lead. Both lead and zinc require very careful laying if they are to be weather-tight.
Thatch protects the interior of a house well from extremes of heat and cold.
[CHAPTER XXXII.]
CONSTRUCTION OF THE HOUSE.
In preparing to build a house, or in entering into a house already built, the following requisites should each receive careful attention:—
1. The site of the house should be healthy, and its relation to surrounding objects in accordance with the laws of health. (See page [201]).
2. The house should be warm in winter, and cool in summer.
3. It should be always dry.
4. There should be an abundant and uninterrupted supply of air.
5. The water supply should be abundant, conveniently arranged, and pure.
6. The excreta and waste-water should be immediately removed from the house and its annexa.
The three last requisites have already received consideration. Of those still to be considered, dryness is the most important. A damp house is certain to be an unhealthy one. It is this for two reasons:—1st, it is a cold house, as damp walls, like damp clothes, conduct the heat of the body away much more rapidly than dry walls; 2nd, if the pores of the bricks are occupied by water, air cannot pass through, and thus the ventilation and purification of the house are greatly impeded. Damp may arise from the ground on which a house stands, or from the rain beating against the walls, or from a defective roof. Unless special means are taken to prevent it, moisture rises by capillary attraction through brick after brick.
The Foundation requires to be solid and substantial, otherwise sinking occurs, with cracking of the walls, resulting in an unsafe condition, and an exposure to rain and wind.
In making the foundation for a house, the ground should be excavated, so as to secure a solid bed of earth or rock not liable to be affected by the weather. A continuous bed of the best cement concrete should then be laid, not only under the walls, but covering the entire site of the house, and extending on every side at least 6 inches beyond the footings of the wall; and for footings it should never be less than 18 inches thick. The concrete serves two purposes: it, to a large extent, cuts off the entrance of the ground-air through the basement floor into the house; and prevents the entrance of damp into the house from below. To further ensure dryness where the floor is below the level of the adjacent ground, a dry area is frequently provided, that is, a closed chamber lined with stone or cement below the ground level of the house, and surrounding the underground part of its four walls, or a hollow wall is built below the ground-level, as shown in Fig. 38. Neither a dry area nor a hollow wall constitutes the best arrangement, as the cavity is usually inaccessible, and rather aids than hinders the entry of the ground air into the house. The best plan is to provide a solid wall, impervious to both moisture and air. A vertical layer of roofing slates is sometimes used for this purpose; or, still better, a narrow cavity about ½ to ¾-inch wide is provided in the body of the wall, and this is run full with molten asphalte.
The Walls of the house must be provided with a “damp-proof course” carried through their whole thickness, slightly above the highest point at which the ground is touched. It may be formed by (1) sheet lead, which possesses the disadvantage of being costly; (2) two layers of ordinary roofing slate, set in cement, with broken joints,” i.e. the joints of the upper layer over the centre of the slates below them; (3) a layer of good asphalte, about ¾-inch thick; (4) perforated glazed stoneware slabs; or (5) two or three courses of hard blue Staffordshire bricks, laid without mortar. The use of asphalte is an excellent plan, and is now commonly adopted in good buildings.
Fig. 38.
Double Damp-Proof Course and Hollow Wall.
a, a—Damp-proof courses. b—Level of neighbouring ground. c—Floor-boards. d—Floor joist. f—Vertical space in wall. g—Concrete under foundation and over site of house.
This suffices when there is no basement. If there is a basement an open area around the house is desirable. Where for a given wall this cannot be secured, the vertical damp-proof course already described must be made to extend from the foundations well above the ground level. The open area, however, should be insisted on whenever practicable. The damp-proof course protects the walls from damp proceeding from the soil around or beneath the house.
It is necessary also that the walls above the level of the ground should, as far as possible, be kept free from damp. Damp walls, not due to ascent of moisture, may be caused by
(1) Rain falling on window-sills which do not project beyond the walls, and consequently do not throw the water clear of them. This is remedied by constructing the window-sills so as to project beyond the walls, and “throating” them to prevent rain from running along the bottom of the sill. The throat is shown at a, Fig. 39.
(2) Rain falling on cornices and other projecting portions of the wall itself. The evil from this source may be diminished by sloping the top of the projection, downwards from the face of the wall.
(3) Parapet walls, gables, etc., not being properly covered with coping. All such walls should be topped with a projecting slab of stone, or with a damp-proof course under the top course of bricks, which should be laid on edge.
(4) Overflow from defective roof-gutters or rain-water pipes. In this case, either clearing out, repairing, or renewing is required.
(5) Rain beating against the walls. This as a rule produces no great harm, if the walls are well constructed. Most of the water runs off as it falls on the surface. It is advisable, however, to protect a much exposed wall by a coating of Portland cement, or in extreme cases with slate. Various impervious paints have also been employed.
Fig. 39.
Section Through Window.
Showing stone sill “weathered” at i, and “throated” at a. b—Wall. c—Inside plaster of room. d—Window-board. e—Oak sill. f—Beading and g—bottom rail of window-sash. h—Window. j—Iron tongue let into slot in i and e to prevent rain driving in.
If it is not proposed to coat exposed surfaces of brickwork, the wall may be formed of two parallel walls, two inches apart, and tied together by a sufficient number of bonding-ties of iron or glazed stoneware, or some other non-absorbent material. This arrangement is shown in Fig. 40.
An excellent plan is to fill in the narrow space between two such walls, as the building proceeds, with asphalte or slab slate, thus forming a vertical damp course, in the same way as below the ground level. The evils arising from damp can be avoided in every new house by proper methods of construction. In an old house, however, they are much more difficult to remove. The dampness is indicated on entering, by a peculiar mouldy smell, and by the discolouration and destruction of wall-papers, and dry rotting of floor timbers. In such a case a damp course may, with care and patience, be inserted in the wall, and the soil under the basement may be covered with concrete, and a dry-area excavated around the basement. Free ventilation under the floor-boards of the lower floors also helps in keeping the house dry.
Fig. 40.
Showing Hollow Wall and Bonding-ties of Glazed Stoneware.
a—Cavity. b—Tie. c—Floor-joist. d—Wall-plate. e—Concrete foundation of wall.
The thickness of the walls of a house requires to be sufficient to ensure stability, to keep out the damp, and to prevent a too rapid loss of heat from the walls. The relative merits of the different materials employed for these purposes have been already considered. A thin-walled house is hot in summer, and cold in winter. The upper stories of houses are often built with too thin walls, the result being chilly bedrooms. A single-brick wall (9 inches thick) will rarely keep out the weather effectually, and frequently a brick-and-a-half wall (14 inches thick) is insufficient for this purpose. The bricks should be so interlaced as to “bond” or tie the wall together in all directions. The strength of walls may be increased by the introduction of hoop-iron between the courses of brickwork.
In the construction of fire-places and chimneys, it is important to avoid the proximity of timber and wood-work to the inside of flues, as this is a common cause of fires.