Severe hail damage can involve splits in wooden roof shingles. On asphalt shingles, hail can cause severe granule loss. In these cases, a portion of a roof, or the entire roof, may need to be replaced after the storm.
If the hail is smaller, damage to the roof may be mild. Mild damage will appear as small indentation marks that should dissipate over time and not effect the life of the roof shingle. In this case, the damage is cosmetic and is not a cause for alarm.
A 2009 San Angelo Standard-Times article explains that although significant damage doesn't usually occur unless a hailstone is at least the size of a golf ball, small hailstones can cause tiny exposures in the shingles, which can develop into damage over time.
To properly assess hail damage, it's necessary to schedule an inspection by a qualified roof specialist. Many insurance companies will not cover the cost of hail damage without a professional roof inspection.
There is no such thing as a fully hail-proof roof, according to Roofhelp.com. However, individuals can invest in hail-resistant roofs. Most roofs are awarded ratings based on their ability to weather a hailstorm.