CEMENT FLOORS

Dominion, Volume 23, Issue 53, 26 November 1929, Page 8

CEMENT FLOORS

MERITS AND ADVANTAGES SOUND AND FIRE-PROOF The use of Portland cement for floors in residences is certainly increasing, but, strangely enough, it is being applied only to the ground floors, not. to the upper storeys. It is rather odd that builders have not awakened to the advantages of using concrete for the upper floors. In America where, we must confess with shame, they take more notice of the great utility of concrete, floors of this material are very frequently used, but even there the building trade has a tendency to cling to timbers and planks. The opinion that is sometimes expressed by the housewife is that concrete floors are “so' cold,” but. the floor, no matter what it may- be composed of, is no colder than the air surrounding it. In the room iu which this is being written there is an ordinary wood floor covered entirely with a very thick cork lino, and over that is a high-grade Turkey carpet; yet the floor of this room in winter is far colder than an upper room in the same house which has a concrete floor but is differently situated. It is just a matter of position. When a concrete floor is laid on the damp clay it will always be cold, but if it has a few inches of air space and is laid in suitable hollow tiles, the floor cannot be colder than the air, and because of its imperviousness it will let the cold air up through crevices, such as there are between planks; therefore a room with a concrete floor must necessarily be warmer in cold weather than one 'with a wooden floor.

So much, then, for the objection; but but what of the advantages? These are many, especially 'with regard to upper storeys. When we consider that in practically all the new hotels, big stores, blocks of oflices, and similar buildings now being erected the floors are all of concrete, it is obvious that there must be some advantages over and above those of mere conveniences of building and cheapness. Perhaps the most important of all is that the floors are fireproof. In ordinary homes fires occur from several causes; oil stoves may be upset, curtains may blow on to an exposed gas'flame, there may be a short circuit in badly laid cleptric wires, hot coals may fall from unprotected fireplaces, or a neglected caudle may set fire to a bed. These are some of the main causes of fires, and it will be seen that in practically all of them, if the floors were made of concrete, much danger and almost all danger would be eliminated.

So much for fire; now let us consider water., The children leave the tap on in the nursery wash-basin, and water overflows on to the floor and is noticed when the drawing-room ceiling is damaged, or similarly in the bathroom. Also, in winter, when a pipe freezes and bursts, always there is much damage to the rest of the house. Very little of all this would occur if the floors were of impervious concrete.

Concrete is also more sound-proof than the ordinary wooden floor, and this, in a house containing children, a gramophone, and a loud-speaker, is a decided asset. From the point of view of the property owner concrete floors are exceedingly valuable, because they do not wear out or suffer from dry rot. Consequently, there is far less deterioration and call for repairs. A properly constructed concrete floor binds the whole house together far better. than do timber hinders and joists, and thus the building yields less to vibration from the passing of trams and -’buses in the - street. Moreover, the romping of the most strenuous children will not be likely to shake the pictures on the walls.

It will be noted that considerable stress is laid upon the activities of children in houses; many architects and builders seem to think that houses are intended only for occupation by the sedate and elderly instead of by a mixture of these and their opposites. Further, in regard to the structure, the cracking of plaster walls that is often caused by the shrinkage of improperly seasoned joists, cannot take place when the floors are made of properly laid concrete, In addition to which rats, mice, and other vermin meet their match when they attack cement. The objection that concrete floors are so hard to the feet is not one that need be taken very seriously, as, except forballrooms, which call for special consideration, springiness in the floor is not a requisite; the necessary softness and “give” for ordinary household needs may always be obtained by the use of wood blocks, linoleums, felt, or carpets* or a combination of some of these. Wood blocks may be either tongued and grooved and laid in some suitable cement, such as bitumen, asphalt, or on slag wool; if of sufficient length they may be nailed down. It is not advisable to use wood battens sunk into tlie concrete before it is dry for this purpose, as the wood is liable to rot ; it is prefeable to insert coke breeze blocks, which will take the nails. It might be ebiected that the laying of wood blocks will counteract the fireproofness ol the concrete, but this is not so, lor even if the wood blocks did catch lire they would soon go out because of the lack of sufficient draught to keep them burning. Always the concrete should be allowed time thoroughly to dry, otherwise the moisture might give rise to dry lot the blocks laid upon it. , For some purposes tiles may be laid and the floors furnished with rugs, while for getting more splendid effects, there are a number of makes of imitation stone and marble which are very beautfiul and no As d re-’a°rds J the construction of the concrete floor there are several methods which can be adopted. For ordinary small rooms a single slab can be used, which if suitably thick, will answer any noimal calls that are likely to be put upon it The average house is calculated to . ic quire a floor which will take a weight of 1 3-8 cwt. per foot super, and a p operly reinforced single slab up co lb'L in width will stand up to the call it made Gin. thick. A 12ft. floor should be mn. thick, and for a 10ft. floor 4iu. will suffaCln some situations the beam and arch construction is favoured, which is more expensive to build, though it uses less material. Owing to its composition the substance of a concrete arch is homogeneous, and theoretically, therefore, there is no thrust upon it, consequently large spans can be erected very economically But in practice it is not quite like this’; absolute 100 per cent, homogeneity is not obtainable, and the size of arches for floors is more or less restricted by a number of considerations that must of necessity enter into the building of houses. It is found convenient for the purpose of building beam and arch floors to use the stout sheet iron "pans'’ which run about 4ft. long by 16in. wide ami dip. deep. These are supported in rows on timbers, which in turn are kept up by 4 by 4 posts. The timbers then form the bottoms of the "beams” when the concrete is put on, aiid thus Is formed the beam and arch const ruction. All the concrete should be laid at one time, and the surface finished to a true plane by beating' with a heavy screed. From ten to fourteen days should elapse before the centring is removed. The beam and arch system is a very satisfactory method of laying concrete floors, though, from personal experience, it does not appear to be so sound-proof as some of the other methods, This is also more noticeable when channel tiles are used in the construction ; if concreto blocks are used instead the defect is not so apparent. The principal advantage of this method of flooring is that the underside. if placed upon a suitable layer of expanded-metal, is flat and ready for the ceiling plaster of the room below. The beams between the rows of tiles or blocks ‘ will be reinforced with rods. I It must be understood, of course, that’ as floors made by any of these methodal

are thinner than ordinary wood floors, there is that much more space in the rooms without any increase in the height of the building. This is a decided advanMf the work is being done in hot weather, the surface of the setting concrete should be wetted from time to time to prevent its cracking. Sun-traps, loggias, open-air. lounges, and the like are growing more popular every day, and the floors of these lend themselves to a variety of artistic treatments, for it must be remembered that it will be of little pleasure to the houseowner if the floor of his sun room looks as uninviting as an ordinary street pavement. The surface may be coloured and smoothed with a filler, and then polished with wax in such a way that it resembles old worn stone or some artistic tiling.

With regard to the. checking of the conducting of sound from one room to the other, it is now possible to have the ceilings and walls treated with an acoustic preparation that has the effect of deadening sounds to a degree that is little short of marvellous. In busy commercial buildings where it has been used its success has been most striking, and it is equally useful for private residences. —Fred Grove-Palmer, A.T.C.. in the “Illustrated Carpenter and Builder.”

Brick fireplaces are a feature of many modern houses but they are not so easily kept in good order as the tiled varieties. Naturally, the rough surfaces take up and held a certain amount of dust. The fireplace will be all the better for an occasional scrubbing, and if this is done fairly regularly, should need no further attention. But if the bricks need a little brightening, a sponging with vinegar will have the desired effect. After the vinegar, rinse well, with clear water.