I am residing the south side of a house here in <!—-><!—-> <!—->Minneapolis<!—-><!—-> with a double course of red cedar siding. I am using 18†primed shingles with a 11.5†exposure as that was what I took off the house and must now match up and weave the corners of the adjacent walls. Current practices indicate a nailing pattern of 2-4 nails nailed one inch above the butt line. This leaves the exposure hanging free and covers the nails with the course above. Previous construction (which I removed and which exists of the adjacent walls) has the exposure nailed down with casing nails. Aside from esthetics, and a possibility (remote) of leaks thru those nail penetrations, are there any reasons to not nail down the exposure