What are FCR and MCR
FCR (Fibre Concrete Roofing) is a new roof covering technology. It consists of concrete tiles made of cement mortar mixed with a small amount of natural or synthetic fibre.
In the case of MCR (Micro Concrete Roofing) fine aggregate is used instead of fibre.
For further basic information please refer to The Basics of Concrete Roofing Elements.
The advantages of FCR and MCR
The technology provides an inexpensive and reliable roof cladding and suits especially the needs of developing countries. The main advantages are:
· The raw materials are available locally and thus foreign exchange is saved.
· The appropriate technology that is involved allows for decentralized and small scale production.
· The technology involves little investment.
· The production is labour intensive rather than capital-intensive, thus it creates jobs.
· During sun radiation, compared to metal sheeting, rooms covered with FCR/MCR remain cooler because of better thermal insulation and ventilation.
· During rain, compared to metal sheeting, FCR/MCR produces much less noise.
· The product is environmentally well adapted.
· The technology is easy to learn.
The drawbacks of FCR/MCR
The durability of FCR/MCR is basically as good as for ordinary concrete tiles, which have shown service lives exceeding 50 years. However, lower strength of the material compared to modern concrete tiles and AC-sheets was sometimes achieved because of the small production units involving a risk of bigger variations in quality and because of the lack of standards.
Objectives of the guide
The roof constitutes the most important part of a building and special care has to be taken in preparing the roof and the roofing elements. The best available raw materials should be used and throughout the production process it should be kept in mind that a bad quality roofing product will not only result in a failing roof but may also lead to severe damage to the whole building.
To promote the FCR/MCR technology a high and constant quality is required. This is not only needed to gain and maintain a reputable product but also because misinvestments can not be afforded. Therefore, adequate technology transfer and comprehensive dissemination of know-how are important tools in the production process of FCR/MCR.
This guide is compiled to facilitate advisory centers to transfer this know-how systematically, and to help producers to achieve a high standard product. The chances of improved production on a broad basis are then increased, benefiting from the well established technological know-how that exists.
What can you find in this guide:
The guide provides detailed technical guidelines for daily use in the workshop, the rules and hints how to produce FCR/MCR tiles.
What can you NOT find in this guide:
The guide is intended for persons who already know the basics of FCR/MCR or even are producing FCR/MCR elements.
As a consequence, it does not contain
· the basic information required for new-comers such as advantages and disadvantages, and guidelines to be considered as first steps towards FCR/MCR.
It also does not contain
· information on production
· specifications of cost and profit
· information about particular problems in particular countries
· guidelines for quality control and the required tests
If you are interested in basic information we suggest to read
the following booklet:
The Basics of Concrete Roofing Elements. Fundamental Information on the Micro Concrete Roofing (MCR) and the Fibre Concrete Roofing (FCR) Technology for Newcomers, Decisionmakers, Technicians, Field Workers and all those who want to know more about MCR and FCR. (available at SKAT free of charge in English, French and Spanish).
If you are interested in scientific explanation and justification for specific recommendations we suggest to read the Technical Memorandum No 16: Fibre or Micro Concrete Tiles, Production Process and Roof Laying (available at ILO in English and French).
The guide is not designed as an instrument for self teaching. For a successful work many additional hints and tricks are needed that can only be acquired with a comprehensive training.
Other elements of the FCR/MCR Toolkit as well as further information are available from SKAT or ILO.
Testing the quality
All along the process of producing tiles, a quality control process should be applied. For this purpose a separate tool has been published in this serie: Quality Control Guidelines, Toolkit Element 23. In this manual a comprehensive methodology is proposed and described, including quality control on raw material, production process, and the end product. There is a sound complementary between both manuals.
Managing the production
This guide describes the production of the tiles step by step. The reality in the production process, however, is much more complex. Many steps are carried out simultaneously, in sequences or in cycles that may be interlinked or overlap. How this production process can be organized is described in the Production Management Guide, element 21 of the Toolkit.
The Production Management Guide uses the same numbering system used also in the Production Guide and also in the Quality Control Guidelines. This eases the use of these three elements side by side.
Validity of the data:
The rules and data presented in this guide are based on scientific laboratory research and long standing practical experiences by international technology specialists, and represent a general average. Data such as the mix to be used, compaction and curing time etc. may vary slightly from place to place, depending on the raw material properties and other local factors. Experience in a particular country will provide the exact data that are to be applied.
Range of products:
The process described in this guide is basically designed for the production of tiles, both the Roman type and the Pan type. By adapting the rules analogously, the same method can, however, also be applied for the production of semi-sheets and the various fittings which are required for different roofs types.
The sole responsibility that the rules are implemented correctly should lie with one person (i.e. the head of the workshop). He should also make records and keep them for at least five years.
Comments and feedback information are welcome and will help to further improve this guide and with it the technology. They may be sent to SKAT or ILO.