After three weeks of dry weather, the roofer has made some real progress.
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| Edge of roof showing internal layers | 
On top of the concrete, there is a layer of some kind of bitumen/tar, which may or may not be bedded on some sort of insulation.  On top of that are two layers of polystyrene (about 10cm).  Then comes a layer of wood (about 1cm).  Next comes a sort of thick plastic sheeting like you can line ponds with.  That layer is just about finished.  Maybe the pebbels come next - let's wait and see.
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| Roof panorama |