When hail strikes your roofing, it can knock off the protective granules of shingles. These damaged areas become the source of leaks in your roof. Leaks won’t occur immediately, however, and it can often take a few years for them to develop. But it makes sense to replace any damaged shingles as soon as possible—waiting until you notice a leak will only mean that you’ll be paying more, or doing more work, to repair the damage.