I have experience installing Cat5 and have used flexible orange duplex fiber to connect the GBICs of two switches so I volunteered to help run fiber between two adjacent buildings for my church. The fiber will run along the inside of an awning so it will be protected from rain. The Graybar salesman told me that indoor/outdoor fiber should be used because it has a gel that makes it waterproof, but it's about twice the price of the indoor fiber.
Is there really any reasonable chance that water could get inside the PVC jacket of indoor fiber? Even if it did, I have to wonder if it would degrade the Ethernet signal on the link because the fiber is buffered. Basically, I want to know if indoor/outdoor fiber is recommended for this application because there is some theoretical benefit or because indoor fiber will actually fail in this situation after a few years.