In Texas, hail gets the attention. It arrives loudly, it dents cars in the driveway, and everybody on the street knows it happened.

Wind is quieter about it. A thunderstorm outflow moves through at 60 or 70 miles an hour for ninety seconds, and afterward the yard has some branches in it and the house looks fine. Two years later there is a stain on a bedroom ceiling and nobody connects the two.

Wind is worth understanding on its own terms, because it damages a house by a completely different mechanism than hail, it starts at completely different places, and almost everything that makes a roof wind-resistant is invisible once the roof is finished.

Wind does not push, it pulls

The mental picture most people carry is wind shoving against a wall. That is the smallest part of what is happening.

As air moves over and around a building it accelerates, and accelerating air drops in pressure. The result is suction: negative pressure lifting up on the roof surface, pulling outward on the side and back walls. On a typical house, the largest wind loads are not the inward push on the windward wall. They are the uplift on the roof, and the uplift is not even across it. It concentrates at corners, along edges, and near the ridge, where the airflow separates most violently.

This is why wind damage is an edge phenomenon. It does not usually start in the middle of a roof plane. It starts where the roof stops.

The three places it starts

The roof edge. The first courses of shingles along an eave or rake have air moving underneath them at the point of greatest suction. If that edge is not tightly sealed down, wind gets under a tab, lifts it, and then has purchase on the next one. Failure is progressive: once the leading edge goes, the rest of the plane peels in sequence. This is why the IBHS FORTIFIED standard specifically calls for a wider drip edge and a fully adhered starter strip, which "when used together create a stronger system." IBHS states the underlying finding directly in its technical bulletin on shingle installation at roof edges: research at the IBHS Research Center on three-year-old roofs with various edge attachment details "clearly demonstrated the need to ensure that shingles are properly installed and well adhered along the perimeter of a roof." It is a few dollars of material at the most consequential inch of the roof.

The deck attachment. Under the shingles is sheathing, and the sheathing is nailed to the rafters or trusses. How it is nailed decides whether the deck stays on the house. FORTIFIED requires ring-shank nails installed in an enhanced pattern, and IBHS states that "using ring-shank nails nearly doubles the strength of your roof against the forces of winds." Ring-shank nails have rings along the shank that resist withdrawal. The difference between a smooth nail at code-minimum spacing and a ring-shank nail in an enhanced pattern is a small line item on a re-roof and is completely invisible afterward.

The garage door. This is the one homeowners least expect, and it is the most dramatic. A garage door is by far the largest opening in most houses, and when it fails inward the wind is suddenly inside the building. The interior is pressurized, the pressure pushes outward on the roof and walls from underneath at the same moment the wind is pulling up on the roof from above, and the two loads add.

The IBHS field data on this is striking. Post-event field damage investigations after Hurricane Ike in 2008, the Joplin tornado in 2011, and the Moore tornado in 2013 found that 90 percent of homes whose garage door survived the storm had no structural damage to the roof.

The garage door situation in Texas is worse than most people assume. Wind-rated garage door requirements did not exist anywhere in the country before 2006, so any door older than that was never tested for pressure. And an IBHS survey found that 80 to 90 percent of garage doors away from coastlines are not properly labeled, with the label either missing information or removed by the installer or a previous owner. If you cannot find a label on your door, you do not know what it is rated for, and that is the most common condition.

IBHS identifies three failure modes worth knowing: high winds buckling weak garage door tracks, flying debris piercing the door, and inadequate attachment of the door to the building causing it to detach and fail inward. Wind-rated doors are tested to ASTM E330, ANSI/DASMA 108, or Florida Building Code TAS 202, and the Department of Energy notes that a rated door carries a permanent label showing manufacturer, model, positive and negative design pressure rating, and the test standard. That label is what you are looking for when you go into the garage with a flashlight.

A note on that statistic, because it gets flipped constantly: IBHS found that 90 percent of homes whose garage door survived had no structural roof damage. That is not the same as the claim, common on vendor sites, that garage doors cause 90 percent of wind damage.

One free thing: IBHS research has shown that closing interior doors during high wind reduces internal pressure and improves roof performance. If a garage door does fail, a closed door between the garage and the house is doing real structural work.

What actually happens after the covering goes

Here is the part that turns a wind event into an expensive one.

Asphalt shingles are the water barrier. Roof sheathing is not. When shingles come off a section of roof, water goes straight into the seams between sheathing panels and from there into the house, and a storm that removes shingles is a storm that is also raining.

This is what the sealed roof deck addresses. Taping or sealing the seams of the roof deck creates a secondary water barrier under the covering. IBHS states that doing so "can reduce that water-intrusion by up to 95%." It is the single highest-value item available at a re-roof, because it changes the outcome of the event you did not prevent.

IBHS built a research program around precisely this scenario. In 2011 it ran what it called a first-of-its-kind full-house examination of how wind-driven water penetrates common openings in residential roof systems, modeled on post-event damage assessments in areas where winds were strong enough to blow off the roof cover but not strong enough to tear off the sheathing. That is the ordinary Texas thunderstorm case, not the hurricane case.

The other components in the FORTIFIED Roof set follow the same logic. The roof covering itself has to meet high wind ratings: asphalt shingles at ASTM D3161 Class F or ASTM D7158 Class H. Attic vents have to be wind and rain resistant, because a standard vent in driving wind is an open hole pointed at your insulation.

None of this is exotic and none of it is expensive relative to a re-roof. All of it is impossible to add later without taking the roof off again.

What Texas wind actually looks like

Most damaging wind in Central Texas is not tornadic. It is straight-line wind from thunderstorm downdrafts, and the terminology is worth having:

• A downburst is a localized strong wind event caused by a strong downdraft within a thunderstorm. A microburst is a downburst less than 4 kilometers across, and can produce extremely high winds in a very small area.
• Straight-line wind is the term used to distinguish this damage from tornado damage. The debris pattern is directional rather than convergent, which is how survey crews tell them apart.
• A derecho is a widespread, severe windstorm originating from a mesoscale convective system. NOAA's Storm Prediction Center sets the criteria: a swath of wind damage at least 250 miles long, wind gusts of at least 58 mph along its length, and several well-separated gusts of 75 mph or greater. SPC notes that derecho damage "typically occurs in one direction along a relatively straight path," which is where the straight-line term comes from.

That 58 mph figure is the Severe Thunderstorm Warning threshold, equal to 50 knots. It is a lower bar than most homeowners picture, and Central Texas clears it many times most years.

The National Weather Service office in Brownsville publishes a useful plain-language ladder of what different straight-line wind speeds actually do:

• 58 mph. "Most businesses and homes will not sustain damage in such winds. However damage from other objects, such as trees or powerlines can occur and be dangerous."
• 70 to 80 mph, the typical downburst range. "Most homes and businesses will again not suffer significant structural damage in such winds, but significant exterior damage can occur, such as damage to roofs, awnings and siding."
• 90 mph and above. "Most mobile homes will be seriously damaged or destroyed. Many businesses and some homes, especially those that are older will sustain at least some roof damage and some of it may be significant." NWS adds that damage at these speeds looks very similar to an EF0 or EF1 tornado.

For scale on the other side: the residential building code as adopted in Austin (Table R301.2) sets an ultimate design wind speed of 105 mph, three-second gust, Risk Category II. A 75 mph downburst is well inside what a compliant new house is designed for, which is exactly why the failures that do occur cluster at edges, openings, and older construction rather than at whole structures.

If you want to know what has actually happened near you, NOAA's National Centers for Environmental Information maintain the Storm Events Database, searchable by state, county, event type, and date range back to 1950, along with the Severe Weather Data Inventory for radar-derived point queries by latitude and longitude. Neither is searchable by street address, so expect county-level or coordinate-level answers rather than a report on your house. Those are the archival, quality-controlled records; the preliminary local storm reports that circulate right after an event are useful but are not the durable source. NCEI is also careful to note that absence of data for a location and time does not mean no severe weather occurred there.

What to photograph, and when

Wind damage is subtle from the ground, which is exactly the argument for having a record of what things looked like before.

• The roof edge, all the way around. Eaves and rakes, from the ground with a zoom. Lifted, curled, or creased tabs at the edge are the early signal.
• Ridge and hip caps. These sit in the highest-suction area and are frequently the first thing to move.
• Soffit, fascia, and gable-end vents. A soffit panel out of its channel is a direct opening into the attic, and reinforced soffits are a FORTIFIED requirement above the Roof designation for exactly that reason.
• The garage door. Photograph the panels, the tracks, the rollers, and above all look for and photograph the label. Note whether the door bows visibly under wind.
• Fences, gates, and detached structures. A fence section down tells you the direction and roughly the intensity of what came through.
• Trees. Limbs over the roofline, dead wood, leaning trunks, and root plates. Drought-stressed trees fail at wind speeds that healthy trees ride out.

Take the set on a calm day so it is a baseline, then again within a day or two of any significant wind event. Our guide on how to photograph a house so the record is worth something covers the method, and the hail documentation guide covers the soft-metal indicators that overlap heavily with wind.

The one moment that matters

Almost every wind-resistance decision on a house is made on the day the roof is replaced, by whoever is doing the work, usually without any conversation about it.

That is the moment to ask for the sealed deck, the ring-shank nails in an enhanced pattern, the wider drip edge with an adhered starter strip, the wind-rated covering, and the wind-and-rain-resistant vents. The incremental cost is small against the cost of the roof. The cost of adding them afterward is another roof.

Keep the documentation of what was installed: the product data sheets, the invoice line items, photographs of the deck and the nailing before the covering went on. What any of it means for your policy is a question for your carrier and a licensed Texas insurance professional. What it means for the house is not in question.

Our address check reads the public hazard record for a location and tells you which perils are worth assessing where you live. Free, no account, no photos, no payment.

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Home Health Intel documents condition. We are not a public insurance adjuster (TX Ins. Code § 4102). Carrier underwriting decisions belong to your carrier.

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Roof requirements, garage door findings, and field study percentages are from the Insurance Institute for Business and Home Safety, including the FORTIFIED Roof standard, IBHS Technical Bulletin 2016-05 on asphalt shingle installation at roof edges, the IBHS wind-driven rain research program, and IBHS post-event damage investigations of Hurricane Ike (2008), the Joplin, Missouri tornado (2011), and the Moore, Oklahoma tornado (2013). Derecho criteria and straight-line wind terminology from NOAA's Storm Prediction Center; the wind speed damage descriptions are from the National Weather Service Brownsville office and are a local explainer rather than a national standard. Design wind speed from Table R301.2 of the residential code as adopted in Austin. Historical storm data from the NOAA NCEI Storm Events Database and Severe Weather Data Inventory. Garage door labeling from the U.S. Department of Energy Building America Solution Center. This article is general education, not legal, financial, or insurance advice.