How do you install zinc strips in a roof without creating leaks?
Nail them down, the same way your shingles are nailed down. That is, you nail down a course of shingles, then lay down the new course above the last course, working up the roof. This way the next course hides the nails holding down the previous one. At the ridge, before a ridge cap goes on, you also nail down the zinc strips, placed so they will protrude beyond the ridge cap. Finally, the ridge cap goes on. Enough of the zinc protrudes so that the metal gradually leaches out with every rain to impede moss accumulation.