The All-Concrete Dwelling

CHARLES DE KAY February 1 1909

The All-Concrete Dwelling

CHARLES DE KAY February 1 1909

The All-Concrete Dwelling


Reproduced from Smith’s Magazine

THOSE who have always lived in houses built of wood or brick experience a new sensation when they wake in the morning surrounded by a dwelling constructed throughout of concrete. Especially is the feeling novel if the inner walls are left without plaster so that the structure is seen. The ceiling and beams of cast concrete, the floor and lintels of the same material, the walls of block concrete or hollow brick revealing their natural shapes impress one with the solidity of a house as if hollowed out of the rock like those carved in place from the coral reef on the Bahama Islands.

Not long ago the alert mind of Mr. Edison was turned to this problem. His plan

of iron frames representing the molds of a house like the molds in which a bronze statue is cast may or may not be feasible. But in any case he was considering the casting of a number of houses in one locality, about the same in shape and size, which might serve for workmen’s cottages. A very large initial expense would be the iron molds themselves.

Then it would be necessary to find some new combination of concrete, very liquid and yet cheap, which would find its way into all the ramifications of the molds and set properly, avoiding air-bubbles and faults, grasping the metal reinforcements where those are needed in floors* piers, roofs sills and lintels—and in general per-

forming the duty of well-watched concrete in places where the conduct of the material could not be examined from hour to hour and day to day. It would have to act like molten metal in the hollows of a casting. Until this scheme has been worked out, it is too soon to hail it or criticize it.

What interests a host of intending builders of individual homes is the cottage or villa such as an intelligent foreman, directed by an architect who has used his material can erect at a very low cost.

The wood famine which has the United States in its grip was duly foreseen. Efforts to stave it off by appealing to Congress have failed owing to the power of privileged interests. The frame house gets costlier every year, while Portland cement, which forms the dearest ingredient of concrete, tends to lower prices as the demand for it, extending year by year to more colossal proportions, increases in all parts of the world, and nowhere more rapidly than in the United States.

At present and until frames and molds of

metal are perfected, wood is used for the casting of all or some parts of a concrete building. Of course a cheap grade of wood is used for these frames, yet they form no inconsiderable item along with cement, labor, sand, gravel or other filler. But, on the other hand, the same boards can be used again and again as the lower parts of the building set and the upper parts come to be cast. Moreover, in the end they can be utilized for various minor purposes where wood is more convenient than concrete, though it should be remembered that wooden boards against which concrete has set become refractory to carpenters’ tools. Indeed they turn more or less fireproof, owing to absorption of the more fluid parts of the wet mass.

Given a building of a simple shape, from two to three storeys high, in a locality where sharp sand and gravel or broken stone are to be had, and a competent builder should have no difficulty in erecting a dwelling of concrete as cheaply as, and perhaps cheaper than, one of wood. In moun-

tains where wood can be had cheaper because at hand, and where the sand and gravel have to be hauled from a distance by rail or cart, one must be prepared to pay more for a concrete than for a frame dwelling. Even so, it may be cheaper in the long run, owing to saving in repairs and because of the danger of brush fires in autumn and spring.

Long Island, which suffers from these fires and affords the bulkier ingredients of concrete almost everywhere in the soil ready to hand, is an ideal country for concrete dwellings; parts of New Jersey scarcely less so. It is not surprising, therefore, that from Barnegat to Montauk Point this material for building is rapidly gaining ground on wood.

Where owners of estates need garages and new stables and additions to old farmhouses to accommodate workmen they are using concrete. When a wing to the villa is added, it is generally of the fireproof material, unless it goes too much against the grain of the proprietor to mix styles.

A very interesting example of repeating a colonial house throughout in concrete from an old wooden original is to be seen at East View on the Cockran estate up the Sawmill Valley above Ardsley-on-Hudson.

Here the problem given the architect, Robert W. Gardner, by Mr. Alexander Cockran was to preserve an ancient dwelling with revolutionary antecedents from the slow but sure inroads of decay. While he introduced bathrooms, heating apparatus, and electric service, and added certain balconies not in the original, Mr. Gardner kept the dimensions and divisions of the house, the old-fashioned kitchen, the steep roof. Everything has suffered a sea-change into something that neither mold nor insects nor rats nor fire nor water can affect. Two old wooden hearth fronts alone, and some of the old cupboards in the kitchen, have been replaced in their former quarters.

This house, however, is not to be regarded as a specimen of what is needed by the intending home-builder, for on the one hand such a duplication is very costly, and on the

other it is not well to follow inner arrangements or outlines suitable in wooden construction when the material is so very different.

For summer use, particularly, the concrete house offers opportunities. The walls can support tremendous weights with ease, it is possible to have large airy living rooms, dining room and kitchen on the ground floor, bed rooms on the second, roof terrace, loggia, etc., on the top. Access to the covered loggia can be made by concrete flights of stairs of easy grade. Or it may be well to have an outside stairway to the roof garden, making a very handsome feature of this, as one often sees it done in northern Italy and southern France.

Owing to the material, there is no objection to creeping vines against the walls, tubs with trees on the open roof, flowers in stationary receptacles on window sills. With proper arrangements to discharge the water, such roof-gardens, commanding the finest views, add very greatly to the enjoyment of a summer house, and permit the family to sleep in the open air, if desired, or under the shelter of the loggia roof where the ail passes unrestrained and one does not need to take up one’s bed and walk in case a shower comes on.

A cottage on a rising ground among woods gives from its level roof a charming view of tree tops. In fact, by this construction the part played in summer life by the veranda is transferred to the highest part of the house—which is not saying that porches and piazzas may not also form an item if they are desired. But it is safe to say that if economy calls for only one of these features, the roof-garden and loggia will prove the better investment.

“Monolithic” is the term used for houses which are built throughout of concrete cast in foams. This requires more wood for the forms and takes longer than is the case with those built, as to the walls, of concrete blocks. The latter are made on the spot with block-making machines, of which theie are many varieties to be had. As the blocks have to be turned out of the machines quickly, only so much water is used in the mixture as will permit the block to stand alone when lifted out.

For several days the blocks are kept under cover, being sprinkled from time to time afte** they have set. Then they are removed to the open air and “cured” by

repeated sprinkling until the water has been thoroughly absorbed—until sun and rain have completed their work of “setting” the concrete.

These blocks are not solid but have liberal air-spaces, so that when built into the wall the latter has air within for greater coolness in summer and warmth in winter. If practicable, it is just as well to make the wall blocks for a house several months before the foundations are laid, as they become harder and harder through weathering and repeated sprinkling.

The foundations are cast in wooden frames, and on this cast foundation the walls of blocks rise rapidly. Sills and lintels of doors and windows are framed up of wood and cast in place, the frames being removed when the concrete is thoroughly set, and the boards used again for the upper windows. For floors and ceilings a steel network is a favorite reinforcement, the steel being placed below the middle thickness.

In the concrete beams long twisted rods are used. A wooden trough, representing the coming beam, is roughly built across the space to be spanned. The twisted rods are placed in this trough at the proper distance from the bottom of the trough, which represents the under surface of the coming beam. They are secured by wires. The concrete mixture is then tamped down in the trough, well under the rods, water is added and the whole mass is thoroughly tamped in order to eject air-bubbles and prevent any stones or gravel from failing to be completely encased by the mixture. After a certain number of days the wooden exterior is knocked away and the beam is complete.

Experienced builders consider the state of the weather, if dry or wet. Wet weather is considered favorable. Very hot or very cold weather is not, because direct sunshine is supposed to ary the material unevenly and too quickly, and freezing weather is believed to be dangerous by preventing an equable and thorough absorption of water by the cement. In cases of necessity the too-great heat of the sun is neutralized by canvas screens and the danger of freezing by using means for raising the temperature. As a rule, however, the builder in concrete avoids if possible midwinter and midsummer, for such protective devices entail expense.

Partitions are cheaply made by knocking together broad, flat troughs divided conveniently, and casting in them flat concrete tiles of any desired size convenient for handling. These, after due curing and hardening, are built into partition walls, closets, etc., and thereby decrease the use of wood for the interior. Such houses contain nothing inflammable aside from furniture and hangings, except doors and window frames. Even these may be of metaJ

if the cost is not shunned. Fire starting in a room finds nothing on which to feed. It may char a door or a window-frame, but cannot travel to another room.

In the making of a concrete house each room may have its fireplace and the extra cost will be scarcely appreciable, for the chimneys are built of the blocks and partition tiles. Flues are neatly made of smooth tiles, round which the chimney is built or cast. Ventilation can be secured in the same way; or by making use of the hollows

in the blocks, if the wall is built of blocks and not cast.

Another system which is becoming the fashion is to have the structural parts of cast concrete, but for the walls, instead of concrete-blocks, the hollow tiles that are used for upper storeys of skyscrapers. As these tiles are more or less porous a waterproofing of sharp concrete, made of one part cement to from one to two parts sand, is applied to the outside. This leaves the forms of the tiles visible, but gives the gray

concrete color to the exterior. Bungalows and summer cottages of this sort are practical and cheap.

Color can be applied by treating the concrete when mixed or added afterward in a colored cement solution. Decorative tiles can also be placed in the forms.

Concrete houses afford very serious economies in the labor item, since practically the only skilled labor needed is the foreman. But, as there is always a reverse to a medal, and generally that reverse is poor,

so the trouble in concrete is this. The foreman must be not merely an experienced man but he must be faithfulness itself ; he must be ever “on the job.” No off days, or hours even, for him. He cannot trust the unskilled laborer to keep to the exact mixture, turn the blocks out just right, shade them first, then sprinkle them just often enough. He has to watch with particular care the carpenter who is putting up frames in which to cast beams, stairs and floors, see that the reinforcements of iron are exactly in place, and then, when the frames are being filled, oversee the loaders and tampers at their work lest they scamp their work or disarrange the reinforcement. It is almost always the failure to watch the workman unremittingly which is at the bottom of a failure in concrete.

Cases undoubtedly have occurred where builders have had trouble from their own foolhardiness, expecting the impossible, or neglecting elemental precautions. But usually it is a matter of neglect of orders, where

the fault is hidden by the frames and is not perceived until the props are taken away.

This, and exaggerated statements, as to the cheapness of concrete, are the two things which have done most to keep architects and clients cold toward the manifest advantages of the material.

Concrete is a very ancient material for construction, but reinforced concrete is scarcely half a century old. It is said to have started in a happy idea that came to a Frenchman who wanted large flower-pots for his plants which should not be thick and clumsy. He reinforced them with wire. Nowadays we see glass reinforced in the same way, especially about elevator-shafts.

Coignet and others developed the reinforcement of concrete for buildings, at first merely useful buildings like conservatories. As early as 1874 a concrete villa was built on the north shore of Long Island Sound, but it was many years before the idea “took” here, although in France, Belgium and Germany it was seized upon with avidity.