|FCR: Fibre Concrete Roofing (SKAT, 1987, 185 p.)|
What is FCR?
Fibre Concrete Roofing (FCR) is a building material which has been developed for the covering of roofs mainly in low cost building construction. The roofing elements are shaped and sized in the form of either tiles or sheets. The appearance of the FC sheets is much like that of asbestos cement sheets. The FC tiles look like clay or concrete tiles of grey or red colour. The FCR elements are made of mortar which is a mixture of sand, cement, water and - natural or artificial - fibres.
Roofing - a target for low-cost techniques
The roof is - beside foundations, walls and ceilings - one of the main important construction elements. Therefore it is an important target for finding appropriate technical solutions, especially for the housing of low income groups. The need for alternative methods and materials is increasing since conventional building materials like timber and energy sources (firewood) for clay tile production are in limited quantifies and not available in many places. Also a cementitious material like FCR is less deteriorated by salt or industrially polluted air than steel. This gives the FCR tiles an advantage compared to the corrugated iron sheets.
Why this study?
When we started this study in 1985, the FCR technology was very successful in many projects; on the other hand FCR was harshly criticised in other places. Everybody was talking of fibre-cement roofing, but only few people knew by then that it was in reality fibre-concrete. This little difference of the words concrete and cement, which makes in the reality of building houses such a big difference is typical for the situation of this technology at this stage.
Only few people really knew how to produce good qualify FCR products. Many people and organisations made bad experiences with improper production- and installation- methods. Mainly the unsatisfactory results of FCR production in some projects in the Dominican Republic lead to justified criticism. The result of these criticism was that FCR acquired a rather bad image and aid organisations hesitated to apply FCR in their projects, though it is not the technology or product which failed but its application.
Various parties (institutions and private persons) are active in developing and improving new methods to produce and apply roofing elements made of fibre concrete. Raw materials, production methods, size and shape of the roofing elements differ from site to site. As far as we can judge success or failure of a production plant seems to depend strongly on the personal initiative of the individuals involved. Long term experience with this new technology seems to be very limited, though it is widely used all over the world. Besides many positive experiences the FCR method has also failed in many other places.
At that point of confusion we found it helpful and necessary for the FCR technology and its potential users to get a clear idea of the potential and the constraints of FCR.
We believe that positive criticism of FCR is necessary and that many mistakes
- mainly nonprofessional manufacturing - have been made so far.
On the other hand FCR is a technology which still needs research and development, information, professional training and investigation to become a mature technology which can be helpful in very many housing projects all over the world.
The aim of this study
With this study we want to:
- improve the knowledge of the technical rationale,
- help avoid financial investment into incorrectly planned FCR projects,
- present the latest state of the art of the year 1986,
- evaluate the experience of a large number of existing FCR projects in Latin America, Africa, Asia, etc.
- show the deficiencies of FCR knowhow, application, training, etc.
- show the possibilities of knowhow transfer,
- give clear answers to the questions of the practitioner,
- show the potential and the constraints of FCR,
- show the importance of the aspects marketing, management, economics, acceptance,
- present a follow-up programme.
To help avoid further failures with the useful and in many cases appropriate FCR technology we set out to elaborate a comprehensive package of knowhow transfer mechanisms. The result of this project consists in the presentation of the most up-to-date state of the art, based upon a large number of field experience reports - including good and bad experiences - as well as on laboratory test results. We also intended to show which items need further research and development. The main goal of the project is to propose methods of better knowhow transfer in this field, including professional training facilities.
The project group
In order for SKAT to carry out the study as scrupulously as possible, leading FCR experts were invited to collaborate within a project group. Fortunately some of the best experts - both critics and advocates of FCR - accepted the invitation. The collaboration of advocates and critics within the project group and with outside experts resulted in an impartial presentation of the state of the art of FCR.
To get a relevant number of experiences which could be evaluated, SKAT sent over 50 very detailed questionnaires to sites of FCR production known to the group so far . 20 questionnaires were sent back to SKAT and provided the project group with very valuable facts.
The evaluation of the questionnaires and of the FCR group-members experience as well as several detailed studies and tough discussions within the project group and with outside experts lead to the facts and statements presented in this report . The statements presented in this report are supported by all project group members jointly.
This report is not a manual for FCR production and application. Other publications on FCR - e.g. like The complete text book by John Parry - show how to produce, to manage and to apply FCR. The SKAT FCR report on the other hand shows clearly the limits of application of FCR and the findings which could be drawn out of the experience of FCR producers and users all over the world.
An international consensus
It seems that a consensus of judging the possibilities and the limits of FCR has been found with this study.
The general conclusion may be summarized in the statement, that FCR is a promising technology provided that its knowhow is adequately and comprehensively communicated to all users and followed-up with the help of a world wide network of regional centres specialised in FCR.
The failures so far seem to be the result of insufficient knowhow -transfer, use of faulty production methods and incorrect installation of FCR.
It is our hope that this report will help to show the way in which FCR can con tribute to the implementation of durable and satisfactory low-cost roofing while creating jobs and using local resources.
The need for a follow-up programme
This study has shown that a follow-up is a must if FCR shall become a mature technology and if misunderstanding and failures shall be avoided. Mainly with regard to the growing demand for low-cost roofing materials it is essential that potential and existing producers and users of FCR get additional information on the technical rationale - which also has to be improved. An FCR information network has to be established according to the importance of this technology and to the extremely large number of potential and existing producers and users of this technology.
A follow-up programme has to cover the aspects
- further research and scientific monitoring of FCR to mature
- qualified dissemination of the knowhow as well as appropriate training and technical assistance.