How To Spot Roof Storm Damage | Homeowner’s Guide

Hail damage on asphalt shingles is the number one reason San Antonio homeowners file roof insurance claims, and it is also the damage type that gets missed most often during a self-inspection. Unlike a puncture or a missing shingle, hail impact damage is subtle. What you are looking for is not a hole it is a bruise. A hailstone hitting an asphalt shingle knocks loose the granules that protect the asphalt mat from UV degradation. The impact leaves a dark, circular or irregular spot where the granules have been displaced and the underlying asphalt or mat is now exposed.

What a real hail impact looks like up close: A fresh hail impact on an asphalt shingle creates a soft, dark spot with a slightly indented center where the granules are missing. When you press on a recent impact with your thumb, the spot feels slightly softer or spongier than the surrounding shingle surface because the mat beneath has been bruised. This is different from normal granule wear, which produces a more gradual, blotchy pattern without the distinct circular shape of an impact point.

How hail size determines damage severity: Quarter-sized hail (about 1 inch) is generally the threshold for filing a valid insurance claim in Texas. Marble-sized hail (about 0.5 inches) typically causes minor granule disturbance without the mat bruising that constitutes functional damage. Golf-ball-sized hail (1.75 inches) causes visible denting on metal surfaces and significant granule loss across the entire shingle field. Anything larger than golf-ball size can crack shingles outright and puncture older, brittler material.

The secondary indicators of hail are often more visible from the ground than the shingles themselves. Check your aluminum gutters and downspouts for round dents each dent corresponds to a hail impact and gives you a clear visual record of hail size. Check window screens for pockmarks or tears. Check painted wood surfaces like fascia and window sills for fresh paint chipping or circular impact marks. Check the fins on your outdoor AC condenser unit, which dent easily and are often the clearest hail-size evidence on the property. If hail has left marks on all of these surfaces, the roof almost certainly sustained granule damage even if you cannot see it from the street.

Wind damage on residential roofs follows a predictable pattern. Wind forces work under the edges of shingles, prying up the sealed tabs and breaking the adhesive strip that holds each shingle down. Once that seal breaks, the shingle is vulnerable to the next high-wind event even if it stays in place for months. The danger is that a shingle with a broken seal does not look visibly damaged from the ground. It lies flat. It does not leak. But it is one 60-mile-per-hour gust away from becoming a flying projectile and leaving bare decking exposed to the next rain.

Where wind damage shows up first: The most vulnerable locations on any pitched roof are the edges, the ridge, the rake (the sloped edge), and any corner where two roof planes meet. These are the areas where wind gets the best mechanical advantage. After any storm with winds above 45 miles per hour, focus your ground-level inspection on these locations first using binoculars.

What lifted versus missing looks like: A fully missing shingle leaves a rectangular bare patch of dark felt paper or decking visible from the ground. A lifted or partially missing shingle shows as a tab curled upward or a shingle that appears to be sitting slightly higher or at a different angle than its neighbors. In direct sunlight, the shadow line across the shingle field will be inconsistent where a tab has lifted, which makes it easier to spot.

Ridge cap shingles are the single most common wind casualty on San Antonio homes. They sit at the peak of the roof where wind speeds are highest and they are secured with only two nails compared to the four nails on a standard field shingle. When a ridge cap shingle blows off, it exposes the ridge board and the overlapping top edges of the field shingles on both sides of the ridge to direct water entry. Check the ridgeline from every angle during your ground-level inspection after any wind event above 50 miles per hour.

Most homeowners look at the broad field of shingles when checking for storm damage. That is the wrong place to start. The locations most likely to leak after a San Antonio storm are the transition points: the step flashing along a chimney, the boot around a vent pipe, the metal in the valleys where two roof planes meet, and the drip edge along the eave and rake edges. These are the points where storm forces are concentrated, where debris impact causes the most damage, and where wind-driven rain gets the best angle to penetrate.

After a storm with significant debris branches, leaves, and wind-carried material valley flashings collect all of it. Debris sitting in a valley traps moisture against the flashing and against the overlapping shingle edges on either side. This accelerates corrosion, works sealant joints open, and creates water dams that back rain under the shingles in heavy rainfall. After every significant storm, clear debris from all valleys as part of your immediate response.

Chimney flashing is the most storm-vulnerable flashing type on most San Antonio homes. Step flashing the individual L-shaped metal pieces that run up the side of the chimney between each shingle course can be pried loose by wind or bent by debris impact. Counterflashing the metal embedded into the mortar joints at the top of the step flashing can separate from the mortar during heavy thermal cycling amplified by storm temperature swings. From the ground, look for any flashing that appears lifted, bent at an irregular angle, or rusted from debris impact through the protective coating.

The same storm will leave very different evidence on different roofing materials. A homeowner with a metal roof looking for granule loss, or a tile roof owner looking for dented panels, will miss the actual damage entirely. Each material has a specific set of post-storm indicators that are worth understanding before you do your inspection.

Asphalt shingles: Look for granule loss (dark circular spots), mat bruising, cracked or split tabs, missing shingles, and lifted edges with broken seal strips. In gutters, look for heavy granule accumulation immediately after the storm. Algae-covered older shingles can mask hail impacts because the dark surface hides the granule loss these roofs need a professional on-roof inspection after any qualifying hail event.

Metal roofing (standing seam and corrugated): Hail leaves visible denting on softer metals (aluminum and copper) but may leave minimal marks on heavier gauge steel. The real risk on metal roofing is at the seams and fasteners hail impact and wind stress can separate standing seam locks, back out exposed screws on corrugated systems, and crack the sealant at all overlap joints. Look for denting on ridge caps, flashings, and the flat panel faces. Stone-coated steel panels chip at the coating surface, exposing bare metal to future corrosion.

Tile roofing (clay and concrete): Tile is highly resistant to small hail but brittle under impact from larger stones. Cracked or broken tiles are usually visible from the ground as lighter-colored or irregular shapes in the otherwise uniform tile field. The more common post-storm tile issue is that debris and hail force tiles to shift, breaking the mortar at the ridge or hip caps and allowing water under the overlapping tiles. Check the ridge and hip lines first on any tile roof after a storm.

Not all storm damage announces itself immediately. Some of the most costly post-storm scenarios in San Antonio involve damage that was present from the day of the storm but did not cause a visible leak or interior problem until the next significant rain event which might be three months later. By that point, insurance claim windows may have expired, the original damage has been washed by multiple rain cycles, and separating storm damage from normal wear becomes a more complicated conversation with your insurance adjuster.

Hail can punch through the roofing felt underlayment without visibly cracking the shingle above it. The shingle acts as a flexible cushion that absorbs the impact without breaking, but the felt beneath takes the puncture. Water then has a path through a compromised underlayment but not through the shingle surface. This type of damage produces a slow, intermittent leak that only shows up during heavy sustained rainfall when water pools on the roof long enough to find the underlayment breach. It is essentially invisible on a ground-level inspection and requires a professional on-roof assessment to identify.

Water that enters a roof deck and saturates the plywood or OSB sheathing can cause structural damage to the decking that does not produce an interior leak immediately. The decking absorbs the moisture, begins to delaminate or develop mold, and only shows interior evidence when the saturation level is high enough to drip through the insulation. By that point, a decking repair that would have cost $500 at the time of the storm has become a $3,000 to $6,000 decking replacement with mold remediation. This is the scenario that makes a 30-day post-storm professional inspection genuinely important not just recommended.