Anybody had any experience with long runs of Azek fascia? I have uninterrupted runs of up to 120'. The Azek web site says to leave 1/8" expansion for every 18' of trim, but doesnt really tell you how to do this. Does this mean I have to leave one expansion joint every 18', or can it be cumulative, such as 3/8 in 54'? And then what do you do with the gap, just caulk?