What Is Roof Wind Uplift?

What wind uplift means

When wind hits a house, it has to go up and over the roof. As it speeds up over the top, the air pressure above the roof drops.

The air inside the attic is at higher pressure, so the roof gets pushed up from below and pulled up from above at the same time. That combined force is wind uplift.

It does not need a direct hit. A shingle can be peeled up by suction alone. If wind gets under a loose edge, it acts like a lever and can tear off whole rows.

The FORTIFIED program, run by the Insurance Institute for Business & Home Safety, puts it simply: roof damage often begins when wind gets under the roof edge and starts ripping it away from the home ⁶.

"Wind-resistant roofing" is the everyday name for a roof built to resist uplift. It is not one product. It is a set of tested materials, fastened and sealed the right way.

How a shingle roof resists uplift

A shingle roof holds against wind in two ways. Nails hold each shingle to the deck. A strip of sealant, a tar-like glue applied at the factory, bonds each shingle to the one below it once the sun warms it. Together they make the roof act more like one sheet than many loose tabs.

Research says the glue matters most. IBHS has tested shingles for wind since 2011, and its finding is that the most important factor in high-wind performance for self-sealing shingles is the strength of the seal between shingles ⁵.

The sealant strip along the lower edge is heat-activated, so it needs warm days to bond fully ⁵.

Under the shingles, the deck itself has to stay on. That depends on the nails that hold the sheathing to the rafters. FORTIFIED says ring-shank nails, which have ridges along the shank, nearly double the strength of the roof against wind compared with smooth nails ⁶.

Shingle wind classes

There are two ASTM test methods for shingles, each with its own classes. We read the classes as the National Roofing Contractors Association explains them ³; we did not read the ASTM standards themselves.

The two sets of speeds are on different scales, so a D3161 number and a D7158 number cannot be compared directly. ARMA's own summary lists the D7158 limits slightly higher, at up to 116, 155 and 194 mph ⁴; read the label on your bundle rather than either table.

Why the sealant strip matters

ASTM D7158 only applies to shingles that have a factory-applied self-sealing strip ³. Shingles without one are rated under D3161 instead. ARMA describes the strip's uplift resistance as "paramount for keeping the shingle system intact" ⁴.

That has a practical side. Shingles laid in cold weather may not seal until a few warm days arrive. Until then, a strong wind can lift them. Some makers call for hand-sealing with roofing cement in cold weather or on steep roofs. Ask your roofer what the instructions say for your season and slope.

Worked example: reading the wind rule for a house

Say a homeowner's building department tells them the design wind speed for their site. Here is how the classification statements apply ^{1 2}:

Illustrative only. Your building department sets the design speed for your address. The full table, R905.2.4.1, maps speeds to classes; read it in the edition your town adopted.

Where uplift is strongest on a roof

Uplift is not even across a roof. Wind tends to grab hardest where it first meets the roof and where it swirls: the eaves, the rakes, the corners and the ridge. That is why so much wind damage starts at the edges and works inward ⁶.

This is also why strong-edge details matter. FORTIFIED requires a wider drip edge and a fully adhered starter strip at the edges, which together make a stronger system ⁶.

Our drip edge guide covers the code basics for that metal. Ridge vents and cap shingles sit in a high-wind spot too; one ridge vent evaluation report limits certain uses to set design wind speeds and roof heights ⁸.

Benefits of a wind-resistant roof

• Fewer shingles lost in ordinary storms, so fewer leaks after high wind.
• Less chance of wind getting under an edge and peeling off larger sections ⁶.
• A labeled class you can check on the bundle and the data sheet.
• A stronger deck attachment helps the roof stay on, not just the shingles ⁶.
• A sealed deck limits water damage if the covering is lost ⁶.

Limits of wind ratings

• A class describes a tested assembly. Nail high, nail too few, or skip sealing, and the roof will not perform like the test.
• D7158's standard math assumes Exposure B or C and a building 60 feet tall or less ⁴.
• No shingle rating covers flying debris or a tornado's direct path.
• Ratings do not tell you how well the deck is attached to the rafters.
• Old shingles that have lost their seal may no longer act like their rating.

What drives the cost of a wind-resistant roof

We do not publish dollar prices for this item. These are the things that change a quote:

• The wind class of the shingle line chosen.
• Extra fasteners per shingle where the maker's high-wind pattern calls for them.
• Upgraded edge details: wider drip edge, adhered starter strips, sealed rakes.
• Re-nailing the roof deck with ring-shank nails, which is done with the old roof off.
• Sealing the deck seams, if you follow a FORTIFIED-style plan.
• Inspection or third-party certification, where a program requires it.

How a roofer builds for wind

This is what you should see happen on a reroof in a windy area. It is not a do-it-yourself guide; roof work is a fall risk and a licensed roofer does it.

1. Confirm the design wind speed for the address with the building department.
2. Choose a shingle whose labeled class meets that speed ¹.
3. With the old roof off, check and re-nail the deck to the rafters where needed.
4. Install edge metal and starter strips at eaves and rakes to the maker's or program's detail ⁶.
5. Nail each shingle in the maker's nail zone, with at least four fasteners per strip shingle, or more where the instructions say ¹.
6. Make sure the sealant can bond: hand-seal in cold weather if the maker calls for it.

Nailing pattern: the line on a bid that is really a wind line

The code sets the floor. Under 2021 IRC R905.2.6, shingles must have the number of fasteners the maker's approved instructions require, "but not less than four fasteners per strip shingle or two fasteners per individual shingle" ¹.

Fasteners must be galvanized steel, stainless steel, aluminum or copper roofing nails with at least a 12-gauge shank and a ⅜-inch head ¹.

Where the nail goes matters as much as how many. Each shingle has a nail zone marked by the maker.

Nails set too high miss the shingle below and leave it held only by glue.

Read the fastening line on your quote as a wind line: the number of nails, the nail type, and the pattern for your slope.

Keeping a roof wind-ready

• After a big wind, look from the ground for missing, creased or lifted shingles, especially at edges and the ridge.
• Look for shingle pieces in the yard or gutters.
• Have lifted tabs re-sealed before the next storm.
• Keep tree limbs trimmed back from the roof.
• Have a roofer inspect after any storm that tore off shingles, because the ones left may have lost their seal.

What goes wrong in high wind

• Shingles nailed above the nail zone, held only by sealant.
• Sealant strips that never bonded because of cold weather or dust.
• Loose or narrow edge metal that lets wind under the first course ⁶.
• A deck held by too few or smooth nails, which can lift as whole sheets.
• Once the covering is gone, rain soaks the open deck; FORTIFIED says sealing the deck seams can cut that water intrusion by up to 95 percent ⁶.

Code rules on wind resistance

Section numbers differ between editions and states; R905.2.6.1 is the labeling section in the Florida code and in older IRC editions. This is model code, and adoption and amendment are local.

Uplift ratings for metal and low-slope roofs

Flat and low-slope roofs, and many metal roofs, are not rated with the shingle tests. They use whole-assembly tests.

UL 580 tests the uplift resistance of a roof assembly under steady and pulsing pressure, in Classes 30, 60 and 90; the best assemblies pass all three in sequence, each at higher pressure ⁷.

The 2021 IRC lists ASTM D3161, FM 4474, UL 580 and UL 1897 as the tests for metal roof shingles on a solid deck ¹.

FM Approvals runs its own approval and rating system used widely on commercial roofs. We did not load its rating tables, so we do not quote its classes here. If your low-slope roof has a rating, ask for the listing number and check it against the exact assembly installed.

Wind uplift compared with related terms

Common misconceptions

Myth A 130 mph shingle means a 130 mph roof.

Reality The class assumes the test's nailing, deck and sealing; poor installation throws it away.

Myth D3161 Class F and D7158 Class H use the same speeds.

Reality They are on different wind-speed scales and cannot be compared number for number ³.

Myth Nails do all the work.

Reality IBHS found the sealant bond is the most important factor for self-sealing shingles ⁵.

Myth Wind damage starts in the middle of the roof.

Reality It often starts at the edges, where wind gets under the covering ⁶.

Myth Flat roofs use the same rating.

Reality Low-slope and metal assemblies use tests such as UL 580 and FM 4474 ¹.

Local rules and design wind speed

The wind speed your roof must meet is set by your location, and your building department can tell you the figure for your address. Coastal areas and places with special wind regions usually have higher speeds and stricter rules. Florida, for example, writes its own labeling rule into the Florida Building Code ².

States adopt different editions of the code and add their own amendments. We do not list local wind speeds here, because they come from maps and local tables that change. Ask your building department or your roofer which edition and speed apply to your house.

When wind uplift matters, and what to ask

Wind ratings matter most when you reroof in a coastal or high-wind area, after a storm tore off shingles, or when your insurer asks about the roof. Ask your roofer:

• What design wind speed applies to my address?
• What wind class is on the bundle of the shingle you are quoting?
• How many nails per shingle, what type, and in what pattern?
• What edge metal and starter strip will you use at eaves and rakes?
• Will you re-nail the deck, and with what nails?

Keep going

• Storm damage repairFixing wind-lifted and missing shingles
• Storm damage and insuranceHow wind claims work
• Roof replacementThe time to upgrade nailing and edges
• Roof material selectorCompare coverings for your climate

Related terms

Asphalt Shingles

Asphalt shingles are roofing pieces made from a fiberglass mat coated with asphalt and topped with mineral granules, laid in overlapping rows so water runs off the roof.

Drip Edge

Drip edge is a strip of bent metal flashing installed along a roof's eaves and rake edges that carries water off the edge of the roof and away from the fascia and the deck beneath.

Metal Roofing

Metal roofing is a roof covering made of metal sheets, panels or shingles, most often steel, aluminum, copper or zinc, fastened to the roof deck to shed water, snow and sun.

Storm Damage

Roof damage from a storm event, including hail, wind and falling trees. It is the usual trigger for a homeowners insurance claim.

Roof Sheathing

Roof sheathing is the layer of plywood, OSB or wood boards nailed across the rafters or trusses.

Architectural Shingles

Architectural shingles are asphalt roof shingles made from two or more layers bonded together, so each shingle is thicker than a flat strip shingle and gives the roof a textured, three-dimensional look.

Reroofing

Reroofing is the work of putting a new roof covering on a house that already has one, either by tearing the old covering off down to the deck (a replacement) or by laying the new covering over the old one (a recover, often called an overlay).

Ridge Vent

A ridge vent is a long, low exhaust vent that runs along the peak of a sloped roof, covering a slot cut in the roof deck so warm, damp attic air can escape at the highest point.

Also referenced from: Roof Truss, Roofing Nails, Ridge Cap, Hurricane Roofing