I live on the first floor. The upstairs neighbors deck is just above mine. When it rains there is no protection overhead from the weatheror the ice melting granules she places on her deck. My question is; can i place some sort of plastic under her deck so to protect my deck and keep it dry?
Thank you for any assistance.

If you don't mind a gigantic water balloon bursting over your head occasionally, go right ahead. =)

Actually i was looking for more of a suggestion than sarcasim. But thanks.

They make below deck roofing systems to do just that. they are channel systems that fasten between each floor joist. Afterwhich a plastic insert is secured to the channel. This then directs the drippings out like a roof to the edge of the deck where it can fall down to the ground or into a gutter device to be directed elsewhere.
If your in a condo or townhouse assocation you may not be able to do this without their permission. Perhaps suggestiong this to them so they can install them would be a good idea that I am sure more folks like yourself are suffering from this very same issue.

Thank you. Your input is well appreciated.I will check this out.