What Wind Speed Damages a Roof? Wind Damage to Shingles Explained

The honest answer is that it depends on the condition of the shingles more than on the wind. A useful reference point is the National Weather Service's definition of a severe thunderstorm: gusts of 58 mph or greater, or hail 1 inch or larger.¹ That threshold is about storms, not roofs, but it is the number in the warning you will hear.

A new, sealed, correctly nailed architectural shingle is rated in the lab well above 58 mph. A twenty-year-old roof with brittle tabs and failed sealant may lose shingles in a storm that never reaches severe criteria. In a study of asphalt shingle roofs after a hurricane, IBHS researchers found that older roofs showed more extensive damage on the surfaces, edges and corners facing the prevailing winds, and that gable roofs were damaged more often than hip roofs.³

So the better question is: what does it take to unseal or lift your shingles? The rest of this article answers that.

Two ASTM test methods appear on shingle wrappers and data sheets.

ASTM D3161: the fan test

Specimens are run under a large fan for two hours at 60, 90 or 110 mph. Passing at 60 is Class A, at 90 is Class D, and at 110 is Class F. Any damage, including a sealed tab coming loose, is a failure. NRCA's Mark Graham cautions that the results do not directly correlate to wind speeds experienced in service, since the test ignores building height, exposure and risk category.⁴ Before the test, the deck is warmed to activate the sealant,⁵ which means the rating describes a sealed shingle.

ASTM D7158: the uplift calculation

D7158 calculates the wind uplift on a specific shingle and compares it with that shingle's measured resistance, which depends heavily on the bond strength of its self-seal strip.⁴ ARMA lists the current classes in ultimate design wind speed (3-second gust): Class D up to 116 mph, Class G up to 155 mph, and Class H up to 194 mph.⁶ Those classes assume standard conditions: exposure B or C, a mean roof height of 60 feet or less, and no topographic speed-up.⁶

Older literature quotes lower numbers for the same classes, such as Class H at 150 mph, because it used an earlier wind-speed basis.⁵ That is why you will see different speeds for "Class H" depending on the document's age. Either way, design wind speeds are tied to rare, extreme events, not ordinary storm gusts.⁶

Some architectural shingles carry both. GAF's Timberline HDZ spec sheet, for example, lists ASTM D3161 Class F and ASTM D7158 Class H.⁷

Warranty wind speeds are a different thing

Manufacturers also publish wind speeds in their limited warranties, with installation conditions attached:

• Owens Corning: Up to 160 mph limited wind warranty on Duration Series shingles installed with qualifying Owens Corning system components (hip and ridge, underlayment, starter on eaves and rakes, plus ice and water barrier or ventilation); up to 130 mph otherwise when qualifications are met, per Owens Corning.
• GAF: No maximum wind speed under GAF WindProven, when GAF shingles with LayerLock Technology are installed with four qualifying GAF accessories, per GAF.

A warranty speed describes what the manufacturer will cover if conditions are met. It is not a test rating, and it doesn't change the physics of an unsealed shingle.

Wind flowing over a roof lowers the pressure above the shingles. The pressure difference lifts the shingle and breaks the factory sealant bond. Once a tab rises, more of its surface is exposed and the uplift grows. Fluttering and bending then crease or tear the shingle, and in stronger wind, pieces break off and blow downwind. Failure usually starts at the top of the exposed section, just below the bottom edge of the shingle above.²

A sealed shingle resists that sequence. An unsealed one has already lost its first line of defense. Sealant bonds can fail or never form for reasons that have nothing to do with wind: manufacturing variation, improper installation, aging, cold-weather installation, contaminated adhesive and daily thermal expansion and contraction. Research cited in the same paper found shingles generally stay sealed for roughly their first four to five years in service, after which unsealing becomes more frequent as a normal part of aging.² Our thermal cycling article covers the daily movement side.

Cold weather matters at installation. The sealant needs heat to activate. Owens Corning's instructions say that below 40°F, perimeter shingles must be hand-sealed with four 1-inch dabs of asphalt cement to protect against wind uplift while the adhesive strip may not activate.⁸

The code requires at least four fasteners per strip shingle, using roofing nails with a minimum 12-gauge shank and 3/8-inch head that penetrate the sheathing 3/4 inch or go through it.⁹¹⁰ Where they go matters as much as how many.

On laminated shingles, nails must go through the double-thickness area at the nail line. GAF's bulletin on high nailing gives that line as 5-5/8 inches from the bottom on English-size shingles and 6 inches on metric.¹¹ Nails placed too high can go through the self-seal strip and keep the shingle from sealing, which reduces wind resistance and makes shingles more likely to break off in high winds.¹¹ Under-driven nails, debris in the sealant strip and release tape stuck to the sealant also prevent proper bonding.²

Programs built for wind go further. The IBHS FORTIFIED high wind and hail re-roofing checklist requires six nails per shingle under the high-wind instructions, starter strips adhered at the eave and rake, and shingles with an ASTM D7158 Class H and/or ASTM D3161 Class F rating.¹² See also our wind and hail roofing system.

Wind pressure is not uniform. Damage concentrates in the high-wind zones of a roof: the eaves, hips and ridges,² and earlier studies summarized by IBHS found roof cover damage greatest at corners, edges and ridges.³ That is why the edge details matter so much: starter strips, edge nailing and drip edge. See what drip edge does.

Slope orientation matters too. Inspectors compare damage against the storm's prevailing wind direction. Damage on the windward slopes and edges fits a wind event. Damage spread evenly across every slope, or in a regular pattern, points somewhere else.²

From the ground

• Missing shingles or pieces of shingles, and shingle debris in the yard.
• Exposed underlayment or bare deck showing as a different color.
• Ridge or hip caps that are missing or out of line.
• Shingle edges along the eaves or rakes that look lifted or out of plane.

Up close, by a roofer

• Creases across the shingle, usually just below the edge of the course above. On new, pliable shingles they may only be visible on close inspection and by gently lifting the shingle.²
• Tears through the mat, often at the nail line.
• Missing tabs or pieces, with the fresh edge still attached.

What is not wind damage on its own: an unsealed shingle with no crease, tear or missing piece. And diagonal or "zippered" patterns of unsealed shingles that don't change with wind exposure point to installation or thermal causes rather than wind.²

Do not climb onto the roof to check. Wind-damaged shingles can slide, and an unsealed course gives no grip. Photograph what you can from the ground, note the storm date, and if shingles are missing over living space, call for an emergency tarp. Our storm damage page lays out the sequence after a storm.

Central Texas spring storms often bring hail and damaging wind together, so a storm inspection should look for both. Hail can bruise and crack shingles; wind can crease and remove them. They are documented differently, and our guide to understanding hail damage covers the hail side.

On the insurance side, Many Texas policies set a separate wind and hail deductible as a percentage of your dwelling coverage. On a $400,000 dwelling limit, every 1% is $4,000. Your declarations page shows yours. Policies vary and Texas law requires prompt notice. Practically, file within a year of the dated storm event, and sooner is better because proving which storm caused the damage gets harder as more storms pass over. We document your roof and give you a written report and a scope with named products. You and your insurer handle the claim. Texas law does not allow a roofing contractor to act as your public adjuster or negotiate your claim.

Heat helps here. Shingles installed in a Central Texas summer seal quickly. Shingles installed during a cold snap may not seal until warmer weather, which is why perimeter hand-sealing in cold weather is in the manufacturer's instructions.⁸

A handful of creased or missing shingles on an otherwise healthy roof is a roof repair. Atrium's repair minimum is $250, and most simple repairs are $499 or less. Our rule of thumb: repair wins when it costs under 20% of a replacement.

Matching can complicate it. If your shingle line is discontinued, replacement shingles may not match. Texas has no law that requires an insurer to pay for matching shingles on undamaged parts of a roof. Whether a mismatch is paid for depends on your policy language and your insurer's decision. If your shingle is discontinued, ask your insurer in writing how it will handle the mismatch.¹³ Widespread creasing, many slopes with lifted shingles, or an older roof that has stopped sealing generally point toward replacement. The full framework is in repair vs replacement.