CHEAPER HOUSES THAT LAST LONGER

New Zealand Listener, Volume 18, Issue 461, 23 April 1948, Page 6

CHEAPER HOUSES THAT LAST LONGER

| Written for "The Listener" |

by

R.

AMMER

HERE is an old saying that "a fool can learn from his own experience, but that a wise man learns from the experience of others." This proverb may be qualified by circumstances in which the wise man must gain his knowledge by his own experience in the, absence of other pfoneers, whether fools or not, but it may be said that we, as a nation, have acted like fools with Tegard to building. We have had the experience of hundreds of generations, in all parts of the world, from which to draw our knowledge of materials and methods, yet still continue using temporary materials, even for buildings intended to be used for generations to come. The use of wood, except where a satisfactory substitute cannot be found, should cease as soon as possible (which could be within two years if we have the determination to do it), and fire, Tot, and borer-proof materials should be used for all buildings to be used for over 10 yeats. The cost need not necessarily rise, in fact, it may be reduced. Back to Earth The material that could reverse the present policy of waste to one of thrift is, perhaps, the most ancient, for build_ing purposes, known to man. It is earth! Used with intelligence, and atcording to correct engineering principles, there _is no better substance, and it may become, under mechanisation, the most reliable of all known building materials. By reliable, I do not mean strongest, but a substance that can be calculated to carry a load without having to use a large safety-factor to take care of the uncertainty that is inherent in all building materials. The variation in the quality of bricks, for example, is very great, and the same may be said of wood and _ concrete, In rammed earth building, properly mechanised, the quality of every cubic -inch could be made uniform, and there_fore the whole structure could be calculated very closely, the only safety-factors being those for emergency stresses as -in a hurricane, or earthquake, which have to be considered whatever material is used. Of course there is a lot of prejudice to ‘be overcome before pisé (qa better term than rammed earth) comes into "its proper place in housing the people, and the various articles appearing in the daily papers do nothing to remove the doubts. Indeeq they seem to tend "more to confusion in the public mind as to what is a rammed earth, or pisé_de terre, house. Therefore_I write this in the hope that this confusion may be ‘cleared up, and that a better knowledge of this most arfcient method of construction will lead to its greater usé in housing, if not in industrial and public. buildings. To say a house is of earth is not sufficient, because the method of use makes '@ vast difference in both quality and appearance, as well as in the cost, al-. though the material used may be similar in each case.

The crudest types of earth houses are "wattle and daub," and "sod." The former is a structure of branches and twigs interwoven; the interstices being filled and surfaces brought to near plane with a mixture of mud and straw, or other fibrous substance. The latter, as the name suggests, is built of sods cut from the soil, and laid like very rough brickwork to form the walls, which in some cases, are brought to a more or less smooth surface with mud, or a mixture of cowdung and mud. The more commonly used kinds of earth building are: (1) Adobe; (2) mud or cob; (3) pisé, or rammed earth. Adobe is a Spanish-American term for — sundried brick. This is much used in Mexico, and has been in use in Asiatic countries for thousands of years. In Babylonian times they used sundried brick for office stationery as well. Of course penny postage was not then thought of. I have employed adobe in building many years ago to enable me to compare its qualities and cost with those of cob and pisé, Cob (mud) walls are constructed by at least two methods. The oldest method is to pug the mud by tramping, while adding straw, or other fibrous material. This mud is then lifted by a fork and placed on the wall, and consolidated by the use of a spade, or other suitable implement.- When a course is laid right round the building, and has become sufficiently set, the mud is trimmed with a sharp spade to the correct line, and the process is repeated till the desired height is reached. A less laborious method is that in which the mud is placed in forms, or shutters, as for concrete, and tramped, or rammed to! consolidate it. Some workers omit the fibrous material while pugging and introduce it in frequent layers during the ramming process. The fibrous

stuff serves the double purpose, in either case, of preventing the "pug" spreading too much while wet and distributing the shrinkage over the whole wall. If no "binding" is used, one might get a two-inch wide vertical crack in a wall 10 feet long, when the mud is dry, whereas the binding divides the shrinkage into millions of very small cracks

distributed over the whole wall. Pisé is the product of thorough ramming of screened earth as it is dug from the ground, without adding water (unless the earth is too dry). Heavy moulds are used, and the ramming is continued until the earth has a close, almost rocklike, texture. No "binding" is used because there is practically no shrinkage to combat, and its use would tend to weaken the wall. No Plastering Both adobe, and cob, require plastering of some kind to make a decent finish, but pisé does not. While weeks, or even months, of drying out are required before a cob house is "livable," pisé houses may be occupied comfortably as soon as the roof is on and the plumbing done. The material and labour used in the three kinds of earth house do not differ much, but it is the after treatment to achieve a good finish and great strength that makes pisé stand out by comparison as the best of all. A statement by the Housing Department that if pisé construction had been used by them their output would have been reduced by 75 per cent. implies that the pisé house costs so much more than the average of the brick, concrete, and wood

frame houses that are being built. The Department has been either misreported by the Press, or misinformed with regard to the possibilities of pisé. I admit that in the old method, all manual labour, the man-hour content of earth walls was great, but -in pisé this is balanced by the fact that, if the correct technique is used, there are savings in all these ways: Timber, or other wall material, and cartage;. plaster; labour; reduced: repairs and painting costs; reduced insurance charges; reduced heating costs; no borer to combat. All things considered, and taking a long-term view, a pisé house is a very economical one. While a pisé building is permanent, and will last for centuries, it is warmer and drier than others in winter and cooler in summer. The walls do hot "sweat," and one does not have to hear the weird output of sleeping neighbours. F Vested Interests The fact that pisé is so economical is of course one of the reasons why it is not boosted by the building trades and other interests. The timber men see in its use a reduction in -sawmill (continued on next page)

(continued from" previous page) output. The painters and paint-mer-chants are not in favour of a reduced demand for paint. Plasterers and bricklayers and their suppliers do not want to see houses built in which their services and materials are not required. The plastér-board and paper-pulp manufacturérs probably would not favour building in which the use of their products. is reduced by 75 per cent. The carriers and motor-traders may be averse to the encouragement of the use of pisé because material will always be found on, or near, the building site. The cartage of bricks and concrete materials, and the necessary coal for their manufacture are a large item in building to-day. Then there are the insurance men. Fire-proof buildings mean smaller premiums. Of course, a large-scale use of pisé, and the consequent saving of timber, etc., and labour services of skilled tradesmen would enable more houses to be built, and so absorb the excess; but many people are too short-sighted to see it that way. Speed of Construction With regard to speed of construction, there is no faster construction if properly handled. If the labour is available, the walls of a house from foundations to eaves could be built in one day. There is really only one serious limitation to the general use of pisé in residential

work, and that is its unsuitability for areas subject to floods, or that may become liable to flooding by any future filling or interference with the terrain. This, however, may be overcome in the near future, The timber saved by the use of pisé in one house could go towards two or three others. The plasterers could spread their work over three houses instead of putting it into one. The plumbers and ‘electricians would have to increase their output; the carpet and furnishing men_ would have a busy time. Of course, this would call for some thought and organisation on the part of building and power controllers, but I mention it to stress the influence pisé could have on a problem that has been with us for generations. A re-orientation of our whole internal economy is required to get the best out of these, possibilities, and a return to sanity and industry-is indicated. Instead of high wages being paid to thousands of people who are wasting time, material and power in producing luxury goods, rubbishy doys, gambling services, and other wealth-destroying activities, the people should be directed to useful work. Then it would not be long before every family would be decently housed, fed, and clothed, and life for all made worth while, se |