I have an Airport Extreme base station plus an Airport Express. I am trying to extend my network between two buildings. The problem is, the building that the Extreme is in has a metal roof and the signal is having a hard time escaping. It's not reaching building 2. There is a building in between that I may be able to put the extreme in and then extend with the Express but I'm not sure how well the signal would get back in the building with the metal roof. Any ideas on setup or anything else I could do to boost the signal?