Micro concrete roofing tiles
Practical Action
cement ratio is 0.5). One millilitre of water weighs one gramme, so the weight of water in
grammes is equal to its volume in millilitres. If, after adding your calculated volume of
water, the mix is too stiff, add a little more water but make a note of how much extra is
added. If a water-to-cement ratio of more than 0.65 is needed to make the mix workable
then the resulting tiles will be of low strength and quality, so stop and re-examine your
materials before proceeding.
Place the plastic sheet onto the vibrator unit and clamp down the sides.
Transfer the mortar mix onto the vibrator, spreading it out with a trowel.
Switch on the vibrator unit and
continue to spread the mix with the
trowel. A vibration time of 30
seconds will usually be sufficient.
Figure 7: Making ridge tiles
Vibration for more than a minute is
not recommended: it can cause the
mix to segregate.
Add the tile nib, to be used to fix the
tile to the roof, manually.
Remove the sides of the unit and
carefully slide the green tile, still on
its plastic sheet, onto the mould so
that it takes the corrugated or ridge
shape of the mould.
Stack the moulds and leave
overnight.
Figure 7: Cure in a water tank, in this case an
old oil drum.
Next day remove the tiles from the
moulds and place them in the water curing tank, leaning the tiles against each other.
Leave the tiles in the tank for at least five days.
Remove the tiles from the tank and leave them to cure in the air for at least 20 days in a
cool, shaded place. Sprinkle with water at least twice a day.
References and further reading
Appropriate Building Materials, Roland Stulz and Kiran Mukerji. SKAT, IT and GATE co-
publication, 3rd Edition, 1993.
The Basics of Concrete Roofing Elements. Fundamental Information on the Micro
Concrete Roofing (MCR) and Fibre Concrete Roofing (FCR) Technology for Newcomers,
Decision-makers, Technicians, Fieldworkers, and all those who want to know more about
MCR and FCR. SKAT, St. Gallen, Switzerland, 1989.
An Introduction to FCR/MCR Production: A basin Video. GTZ, Eschborn, Germany, 1990.
Production and Operations Management: MCR Toolkit Element 21 - Production and
operations management for a profitable MCR
Product Information: Micro Concrete Roofing Equipment SKAT
Marketing and Selling Guide for FCR Ikin, D, SKAT
Quality Control Guidelines for FCR SKAT
Production Guide: MCR Toolkit: Element 22 SKAT/ILO Publications, St. Gallen and
Geneva, 1992.
Roof Structure Guide: FCR/MCR Toolkit: Element 24 SKAT
Standards Guidelines for FCR Technology SKAT
Glazing for Concrete Roof Tiles, RAS Technical Bulletin Issue No. 10, SKAT, St. Gallen,
Switzerland, 2000
Roof Truss Guide: Design and construction of standard timber and steel trusses FCR/MCR
Toolkit: Element 29 SKAT
Concrete Roofing Tiles: Building Issues 2 1992 Vol 4. Bo Johansson, Lund Centre for
Habitat Studies, Lund University, 1993.
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