# Hurricane Roof Damage

> Hurricane roof damage is harm done by tropical cyclone winds and rain to roof coverings, decks and framing, typically starting at edges, corners and ridges.

- URL: https://roof.wiki/hurricane-roof-damage/
- Topic: Climate, Hazards & Sustainability
- Also known as: typhoon roof damage; cyclone roof damage; tropical cyclone roof damage; wind damage to roofs; hurricane damage to roofs
- Regions: Global, North America, East Asia, Southeast Asia, South Asia, Oceania
- First published: 2026-11-01 · Last reviewed: 2026-11-01
- Cite as: "Hurricane Roof Damage." roof.wiki. https://roof.wiki/hurricane-roof-damage/

## Key facts

- **Category 3 threshold:** 111 mph (178 km/h): loss of roof decking and gable ends likely
- **Where failures start:** Corners, edges, eaves, rakes, hips and ridges
- **Michael (2018) damage thresholds:** Cover >110 mph; deck >130 mph; structure >140 mph
- **Cyclone Tracy (1974):** About 90% of Darwin houses lost part or all of their roofs
- **Tracy lesson:** Fasteners under cyclic load kept <15% of static strength
- **Florida Building Code:** In effect from 2002, after Hurricane Andrew (1992)
- **Shingle wind test:** ASTM D7158 (2005), in IRC/IBC from 2009
- **Irma + Michael losses:** More than US$100 billion
- **Key mitigations:** Sealed roof deck, ring-shank deck nails, rated coverings, roof-to-wall ties, opening protection

Hurricane roof damage is the harm that tropical cyclones (called hurricanes in the Atlantic and north-east Pacific, typhoons in the north-west Pacific and cyclones in the Indian Ocean and South Pacific) do to roof coverings, underlayments, decks and structural framing. The roof is usually the first part of a building to fail in a severe windstorm, and once its covering or deck is breached, wind-driven rain can ruin the interior even when the walls stand.[3][2] Damage ranges from a few lifted shingles to the loss of the whole roof structure, and the pattern of failure is consistent enough across storms and countries that building codes have been rewritten around it.[1][4]

## How wind damages roofs

Wind flowing over a building does not simply push on the roof; over most of the roof it creates suction that tries to lift the covering and deck away. Uplift is strongest at roof corners, along edges and eaves, at rakes and around the ridge, which is why failures typically start at those locations and why codes require closer fastening there.[6][2] Several mechanisms combine:

- **External suction** peels coverings back from edges, hips and ridges.[2][6]
- **Internal pressurisation** occurs when a window, door or garage door on the windward side fails. Wind then pushes up on the underside of the roof while suction pulls from above, a combination that can blow off whole sections of deck or entire roofs.[2][4]
- **Fatigue** from repeated, fluctuating gust loads can make metal cladding fail around its fasteners at loads far below the static strength measured in simple tests.[4]
- **Wind-borne debris** from damaged neighbouring buildings, including roof tiles and sheets, breaks windows and punctures roofs, spreading damage downwind.[8][5]
- **Water intrusion** follows any loss of covering or underlayment, damaging insulation, ceilings and contents; roof cover loss is the most frequent damage in major wind events.[3][2]

## Damage by intensity

The Saffir-Simpson Hurricane Wind Scale used by the US National Hurricane Center links each category of sustained wind to typical roof damage on well-built frame houses:[1]

| Category | Sustained wind | Typical roof damage |
|---|---|---|
| 1 | 74–95 mph (119–153 km/h) | Damage to shingles, roofing and gutters |
| 2 | 96–110 mph (154–177 km/h) | Major roof and siding damage |
| 3 | 111–129 mph (178–208 km/h) | Loss of roof decking and gable ends |
| 4 | 130–156 mph (209–251 km/h) | Loss of most of the roof structure and some walls |
| 5 | 157 mph (252 km/h) or more | Total roof failure and wall collapse |

Field studies after Hurricane Michael in 2018 found a similar progression: roof cover, wall, soffit and fascia damage above about 110 mph (177 km/h), deck damage above 130 mph (209 km/h), structural roof damage above 140 mph (225 km/h) and total collapse above 150 mph (241 km/h).[3]

## Failure modes by component

**Coverings.** Asphalt shingles fail when nails are misplaced, when the factory sealant strip has not bonded, and at hips, ridges, rakes and eaves; post-storm teams have repeatedly found widespread incorrect nail placement and missing adhesive at hip and ridge caps.[2] In Hurricane Michael every investigated home with three-tab shingles was damaged, while fewer than half of the homes with metal roofs were.[3] Clay and concrete tiles are vulnerable at hips and ridges and become dangerous debris when they come loose.[2][8]

**Ridge vents and soffits.** Continuous ridge vents need a gap cut in the deck; when the vent cap blows away, rain enters directly. Lost soffits let wind-driven rain into attics.[2]

**Underlayment.** Once the covering is gone, ordinary felt underlayment tears or blows away quickly, leaving the deck exposed.[2][3]

**Deck.** Loss of roof sheathing is one of the most common structural failures in hurricanes, and the loss of a single panel can lead to failure of the whole building as internal pressure rises.[6] Gable ends are especially vulnerable where sheathing is weakly fixed to the end truss.[6]

**Structure.** In the most intense storms, rafters and trusses are lifted off the walls where roof-to-wall connections are inadequate, and walls collapse once the roof diaphragm is gone.[1][3]

## Roof shape

Hip roofs, which slope on all four sides, perform better than gable roofs: in Michael, hip-roofed homes fared better than gable or combination roofs.[3] Aid agencies in the Philippines recommended four-sided hipped roofs with minimal or no eave overhangs after Typhoon Haiyan.[5] Large overhangs and flat gable ends catch wind and concentrate uplift.[5][6]

## Notable storms and what they changed

**Cyclone Tracy, Darwin, Australia (1974).** Tracy struck Darwin early on Christmas Day 1974, killing 45 people in the city and 16 at sea. About 60 percent of the city's roughly 8,000 houses were destroyed, more than 30 percent were severely damaged, and about 90 percent lost part or all of their roofs.[4] Investigators identified fatigue failure of cladding fasteners, internal pressures not allowed for in design, and inadequate bracing as the main causes; roof cladding had been tested only under static loads, yet under fluctuating loads its fastenings retained less than 15 percent of their static strength.[4] Darwin's airport anemometer recorded 217 km/h (134 mph) before failing at 3:10 am, and damage evidence suggests gusts above 250 km/h (155 mph); the storm moved at only about 6 km/h (4 mph), prolonging the battering.[4] Australia responded with engineer certification of buildings in cyclone areas, design for full internal pressure, a revised wind code in 1975 with cyclonic zones, and compulsory fatigue testing of roof cladding, formalised in the TR440 guidelines for cyclone product testing; the wind code was revised again in 1989. Buildings certified by structural engineers had survived Tracy relatively intact, and the city was rebuilt to much higher standards.[4]

**Hurricane Andrew, Florida (1992).** Andrew devastated South Florida. The federal post-storm assessment identified failed garage doors as a key route to internal pressurisation and deck blow-off, recommended shingles rated for high-wind areas, and called for a water-resistant secondary membrane beneath roof coverings.[2] The storm led to the statewide Florida Building Code, which took effect in 2002.[2]

**The 2004–2005 seasons.** After Hurricane Charley (2004), homes built between 1996 and 2004 needed 44 percent fewer roof covering replacements than older homes.[2] FEMA's reports on the four storms that hit Florida in 2004 and on Katrina (2005) highlighted roof covering and soffit failures and fastener placement, and stressed following manufacturers' instructions on starter strips and nail locations.[2]

**Typhoon Haiyan, Philippines (2013).** More than a million houses were severely damaged, roughly half of them destroyed, and people were killed by corrugated iron roof sheets torn off by the wind.[5]

**Hurricane Irma (2017) and Hurricane Michael (2018).** Irma made landfall at Cudjoe Key in the Florida Keys on 10 September 2017 as a Category 4 storm, causing almost 100 deaths and more than US$50 billion of damage in the United States, and damage was seen across shingles, metal panels and concrete and clay tiles, concentrated at hips, ridges, edges and soffits.[2] Michael, the first Category 5 landfall in the United States since Andrew, came ashore near Mexico Beach, Florida, on 10 October 2018 with winds of about 160 mph (257 km/h).[2][3] Together, Irma and Michael caused property losses of more than US$100 billion, much of it from roof damage and resulting water intrusion.[2] Homes built under the Florida Building Code performed noticeably better than older homes nearby.[2] Among 186 homes examined after Michael, newer shingle roofs generally outperformed older ones in the same neighbourhoods, and many houses that lost both covering and underlayment suffered water intrusion.[3]

**Typhoon Faxai, Japan (2019).** Faxai damaged many roofs in Chiba Prefecture. Tile roofs laid without following Japan's tile installation guideline often lost or lifted tiles in the main field of the roof, which the national standard (Ministry of Construction Notification No. 109 of 1971) had not required to be fastened; tiles laid to the guideline suffered very little. The notification was partially revised in December 2020 to tighten tile fastening.[8]

## Prevention and resilient design

Lessons from these storms have converged on a set of measures:

- **Wind-rated coverings.** In the United States, shingles are classified for wind under ASTM D7158 (Classes D, G and H) or ASTM D3161 (Classes A, D and F); D7158, first published in 2005, was adopted into the 2009 International Residential and Building Codes.[9][2] The codes require higher classes as design wind speed rises, with only Class H (or D3161 Class F) shingles allowed at ultimate design wind speeds of 168 mph (270 km/h) and above.[10]
- **Stronger deck attachment.** Sheathing at least 15/32 in (12 mm) thick, fixed with 8d nails at least 2.5 in (64 mm) long and 0.131 in (3.3 mm) in diameter, with ring- or screw-shank nails near ridges, gables and eaves where design wind speeds exceed 110 mph and preferably across the whole roof; staples are not recommended.[6]
- **Secondary water barrier.** A sealed roof deck, using taped sheathing joints or a fully adhered self-adhering underlayment over the whole deck, limits water entry if the covering is lost.[2][3]
- **Edge and ridge detailing.** Proper starter strips, correctly located nails, adhered hip and ridge caps, robust drip edges and ridge vents fixed without weakening the deck diaphragm.[2][6]
- **Roof-to-wall connections.** Metal straps or hurricane ties that carry uplift from rafters or trusses down into the walls and foundation; aid groups in the Philippines promoted strapping rather than nailing for metal-framed roofs after Haiyan.[5]
- **Opening protection.** Shutters and impact-rated windows and garage doors prevent the internal pressurisation that often leads to deck and roof loss.[2]
- **Voluntary standards.** The Insurance Institute for Business and Home Safety's FORTIFIED programme sets above-code requirements; its entry level, formerly FORTIFIED Bronze, was renamed FORTIFIED Roof and limited to work roofers routinely perform.[7] In Michael, FORTIFIED and similar above-code homes performed better than neighbouring houses built to the code of their day.[3]

## Regional approaches

- **United States:** wind-rated products and fastening schedules tied to design wind speed maps in the International Residential and Building Codes, with Florida's statewide code and its High-Velocity Hurricane Zone setting the strictest rules.[2][10]
- **Australia:** cyclonic wind regions along the northern coast, engineer certification and mandatory fatigue (cyclic) testing of roof cladding and fixings since the late 1970s.[4]
- **Japan:** a national notification on the structural method of roofing materials, dating from 1971 and revised in 2020 to extend fastening requirements for roof tiles after Typhoon Faxai.[8]
- **Philippines:** post-Haiyan reconstruction guidance favouring hipped roof shapes, reduced overhangs and strapped connections for light metal roofs.[5]

## After a storm

Because water entry through a damaged roof continues after the wind drops, the first priority after a storm is usually to stop further leakage, and post-storm teams also look closely at decks, gable ends and connections that may be weakened without obvious external damage.[3][6] Assessment teams have found that the age of roofing products and the design standard in force when they were installed strongly influence how a roof performs, so storm repairs are often an opportunity to bring the whole roof up to current code.[2]

## Sources

1. Saffir-Simpson Hurricane Wind Scale — NOAA National Hurricane Center. https://www.nhc.noaa.gov/aboutsshws.php
2. From Hurricanes Andrew to Michael: Lessons Learned for Residential Roofing — IIBEC. https://iibec.org/publication-post/from-hurricanes-andrew-to-michael-lessons-learned-for-residential-roofing/
3. Hurricane Michael Wind Investigation: Executive Summary — Insurance Institute for Business and Home Safety. https://ibhs.org/wp-content/uploads/IBHS-Hurricane-Michael-Executive-Summary.pdf
4. Cyclone Tracy: 30-Year Retrospective — Risk Management Solutions. https://forms2.rms.com/rs/729-DJX-565/images/scs_cyclone_tracy_30_retrospective.pdf
5. How to build disaster-resilient homes in the Philippines — Devex. https://www.devex.com/news/how-to-build-disaster-resilient-homes-in-the-philippines-82408/amp
6. Home Builder's Guide to Coastal Construction Technical Fact Sheet 18: Roof Sheathing Installation — FEMA. https://apps.floridadisaster.org/hrg/downloads/FEMA_hgcc_fact18_Roof_Sheathing_Installation.pdf
7. FORTIFIED Roof — Insurance Institute for Business and Home Safety. https://ibhs.org/fortified/fortified-roof/
8. Revision of standards for roof tile installation after Typhoon Faxai — National Institute for Land and Infrastructure Management, Japan. https://www.nilim.go.jp/english/annual/annual2021/pdf_file/1_017.pdf
9. Understanding asphalt shingle standards — Professional Roofing (NRCA). https://professionalroofing.net/articles/article/4817
10. Section R905 Requirements for Roof Coverings (California Residential Code) — GoCodeBook. https://gocodebook.com/library/us/ca/ca-residential-code/chapter-9-roof-assemblies/section-r905-requirements-for-roof-coverings
11. Summary Report on Building Performance: 2004 Hurricane Season (FEMA 490) — FEMA. https://www.fema.gov/sites/default/files/2020-08/fema490.txt
12. Tropical cyclone — Wikipedia. https://en.wikipedia.org/wiki/Tropical_cyclone