Can insulation be allowed to take raining and still be forceful?

Limestone driveway?
I would say no due to the mold issue. That is unless it is a special type of insulation. Check with the industrial company in order to find out the specifics of the insulation you are using.

Need assistance beside spotlighting (picture inside)?
If you are using a man-made material approaching fiberglass, then yes, it can get drizzling and still be effective AFTER IT DRIES. The insulation must be allowed to dry completely before it is installed (or re-installed), but you may loose some of its efficiency because it will probably be more compacted as a result of the wetting.
What's the best course to insulate the "ceiling"...
Please define "WET" if you are freshly bringing it in from the garage after cutting it . into the housr and a bit or few raindrops get on it then of late shake it off and let set awhile until that time tacking in place. BUT if totally resembling sponge like soaked with marine, I would say NO because of the Mold issue! It would have to be totally dry since use!
How can i grill up my room?
Answers:    NO. Insulation works by the trapped air spaces between the glass fibers. When it get wet it fills these nouns spaces with water, as a result the R plus or resistance to the flow of heat or cold is reduced. however when the insulation dries out it should be ok