Yes, I was thinking about using fibreglass as a roof covering, still am. Had not thought of using it as a complete roof though, I prefer to use wood internally as I think it must cut down on condensation. I could be wrong though:.)PH if you are proposing as an alternative to the 'felt' or the 'tin' covering then yes. I would be concerned that an FG roof (without the wooden parts) would not be heavy enough for those windy nights which always occur immediately after I forget to strap things down.
Makes great gliders... . Sigh... Offgassing and condensation are things that bother me a lot. Sick building syndrome comes to mind and I expect can apply to bees too. And yes you will get condensation issues with fibreglass as with glass quilts.200mm sides to make them wind proof and there is the possibility of putting foam in them to increase the insulation value.