Green/Sedum Flat Roof

[technotom]

Has anybody on here got any experience of covering a flat roof with sedum trays?

We have a GRP (fibreglass) flat roof above our ground floor rear extension that would be suitable for this, but it's immediately below our rear bedroom window, so wondering if we might end being plagued with insects when the window is open in the summer. Also worried it might get damaged by pigeon poo and/or turn into a cat toilet, since there's lots of passing traffic!