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close this bookJournal of the Network of African Countries on Local Building Materials and Technologies - Volume 1, Number 4 (HABITAT, 1991, 48 p.)
View the document(introduction...)
View the documentContributions to the Journal
View the documentForeword
View the documentHousing in Africa, problems, prospects and strategies*
View the documentKenya: Towards the development of a national code of practice for structural masonry - the Kenyan approach*
View the documentNigeria: Research and development in the promotion of standards and specifications for stabilized soil blocks*
View the documentEthiopia: Light-weight concrete made with Ethiopian pumice*
View the documentMauritius: Use of calcarenite blocks in housing construction in Rodrigues*
View the documentGhana: Optimum firing temperature for some clay bricks*
View the documentEthiopia: Construction of mud houses - an alternative to the traditional methods of house construction*
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View the documentPublications review
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Foreword

The high rate of population growth and the shortage of affordable shelter, which are prevalent in many developing countries, have reached a point that the need for initiating and implementing urgent actions by governments is becoming evident.

UNCHS (Habitat) has long been aware of this situation and in the light of the Global Strategy for Shelter to the Year 2000, adopted by the General Assembly of the United Nations in December 1988, has launched a number of programmes designed to provide assistance to developing countries in tackling their housing problems. Owing to the fact that development of local technological capacities to deal with this predicament is becoming a difficult task to pursue, technology transfer from one country to another and the establishment of cooperation between countries have become a justified process, the successful implementation of which could lead to the attainment of desired levels of technological self-sufficiency in the countries participating in that process.

In the previous issue of this Journal, the significance of regional cooperation through networking systems was highlighted. The process for the establishment of the Network of African Countries on Local Building Materials and Technologies was described. Roofing materials and related technologies were chosen as themes for that issue. In this edition, focus is given to walling materials and related research work carried out in some countries of the African region.

Roofing and walling materials are the basic materials in the construction of low-cost houses. Bearing in mind that a simple shelter does not necessarily require special finishings and costly mechanical and electrical equipment, the walling and roofing materials constitute, very often, more than 75 per cent of the total cost of a dwelling. Therefore, any reduction in the cost of the production of these materials and improvement of their physical properties will considerably reduce the total cost of a house and will improve its performance.

Results of research and experimental work carried out over the past two to three decades in many countries have shown that low-cost walling materials such as stabilized soil blocks, in terms of their engineering properties, are comparable with fired bricks and concrete blocks, and a wall constructed by these materials should not be considered as being of low quality, and having low strength and limited durability. However, the shortcomings are often associated with the lack of knowledge of the various processes of production, quality control, use and maintenance. In fact, if both producers of walling materials and builders of houses were to adhere to technical specifications, the overall quality performance of houses would be improved and the acceptability and popularity of these low-cost materials would be enhanced considerably. In this regard, adoption of standards and specifications and construction of demonstration houses to show the advantages of such materials to the public are among effective avenues in promoting the wide use of low-cost walling materials.

Acknowledgement and thanks are extended to the authors as well as to the national coordinators of the Network who provided information and data included in this issue of the Journal.

Dr. Arcot Ramachandran
Under-Secretary-General
Executive Director
UNCHS (Habitat)