Damage Repair

Wind Damage Roof Repair

Atlanta's thunderstorm corridor produces wind events that separate membrane laps, pull flashings from parapets, and in severe cases lift entire membrane sections off the deck. Accurate field documentation of what failed — and why — drives a repair scope that does not just cover the visible damage.

Wind damage on commercial flat roofs in Atlanta appears in predictable patterns. Corner and perimeter zones — where building codes require denser fastener spacing for exactly this reason — are where mechanically attached membranes fail first under severe wind loading. Flashing at parapet walls, HVAC curbs, and pipe penetrations separates under uplift pressure when the adhesive has aged or the original installation did not On large-footprint warehouse and industrial buildings, membrane sections can balloon under sustained wind loading before the fasteners release.

Atlanta's thunderstorm pattern drives most of the wind damage we assess on commercial buildings in the metro. High-intensity microbursts embedded in convective storms can produce localized gusts of 70 to 90 mph in areas that the National Weather Service only categorizes as receiving ordinary thunderstorm-level winds. The March 2008 tornado that tracked through Downtown Atlanta and damaged the CNN Center complex produced wind velocities well above what any commercial roof in the immediate path was designed for — but even ordinary severe thunderstorm wind can cause significant membrane damage on roofs where the fastener pattern or flashing adhesion was already marginal.

Our wind damage assessments document what separated, what remains at risk of separation in the next wind event, and what the underlying installation condition was that contributed to the failure. This last point matters: a membrane lap that opened in a 65 mph gust may indicate an existing weak seam, not just storm damage. The repair scope addresses both the immediate failure and the underlying condition.

Common Wind Damage Patterns on Atlanta Commercial Roofs

Corner and edge membrane separation: IBC 2021 wind design requires tighter fastener spacing in corner and perimeter zones than in the field of the roof — 4-inch spacing at corners versus 12-inch field spacing for a typical Atlanta Exposure B mechanically attached TPO system. When buildings are in areas with increased exposure — taller buildings on open sites, buildings near Hartsfield-Jackson's southern approach corridor, or buildings on elevated terrain in the Buckhead ridgeline — the IBC design wind pressure is higher, and the original fastener pattern may be undersized for actual conditions. We check fastener spacing against as-installed conditions during every wind damage assessment.

Flashing separation at parapet walls: The intersection of the flat membrane field and the vertical parapet flashing is the most common wind damage failure point on Atlanta commercial roofs after corner membrane uplift. Membrane termination bars work loose under sustained wind loading if the original installation used incorrect fastener spacing or if the concrete or masonry substrate has degraded. After a wind event, we probe every linear foot of parapet termination on the damaged sections and flag any termination that is loose, brittle, or failing adhesive.

HVAC curb flashing failures: Rooftop HVAC units on curbs create discontinuities in the membrane plane that concentrate wind loading at the curb-to-membrane transition. Curb flashing that was installed without proper strapping or with age-deteriorated adhesive will pull away from the curb under sustained uplift. Atlanta's commercial building stock has a high density of rooftop HVAC equipment relative to northern markets — the climate demands it — which means more curb perimeters per square foot than most markets.

Membrane blow-off on older buildings: Buildings with roofs installed before current IBC wind design requirements — a substantial fraction of Atlanta's 1980s and 1990s commercial stock — may have fastener patterns that do not When these buildings lose membrane sections in a severe storm, the repair must bring the rebuilt area into compliance with current wind design, not simply replace what was there before.

Immediate Stabilization vs. Permanent Repair

After a wind event that has produced open membrane or separated flashings, the first priority is weathertight stabilization — temporary repair that stops water entry until permanent repairs can be scoped and executed. We make a clear distinction between stabilization, which is designed to hold through the next rain event, and permanent repair, which is designed to

Stabilization on a mechanically attached TPO membrane typically means re-fastening separated laps with additional screws and plates and applying a temporary sealant bead at open seam areas. This is not a permanent repair and it does not restore warranty standing. The permanent repair involves cutting back to clean membrane, lapping in new field membrane sections with heat-welded seams, and returning the fastener pattern to the correct density for the zone.

For buildings where wind damage has exposed deck — the worst outcome in a severe wind event — we prioritize dry-in within the same mobilization: temporary single-ply secured over the open area, weighted at edges, to prevent water entry until the permanent scope is executed. Atlanta's afternoon thunderstorm pattern means a building with open deck from a morning storm event will likely see rain within 24 hours.

Wind Design and the Atlanta Building Inventory

Most Atlanta commercial buildings are designed to IBC Exposure B wind criteria — suburban terrain with moderate shielding from surrounding structures and vegetation. Taller buildings in the Midtown or Downtown core, buildings on exposed ridge terrain in Buckhead, and buildings in the open industrial terrain south of the city toward Hartsfield-Jackson may require Exposure C or D design criteria. When the original building was designed to a lower exposure category than its actual siting warrants, the roof system's wind resistance is systematically undersized.

Georgia Building Code adopted IBC 2018 as its current reference, with local amendments. Wind design requirements have tightened significantly from the 1990s code cycles under which most of Atlanta's existing commercial inventory was built. A building permitted in 1995 to then-current SBCCI wind requirements may have a roof assembly with a design wind resistance 20 to 30 percent below current IBC requirements for the same building and location. This is not a code violation for existing buildings, but it is relevant information when assessing why a roof failed in a storm event and what the permanent repair needs to achieve.

Our wind damage assessments include a review of the as-installed fastener pattern, the membrane attachment method, and the building's location relative to its designed exposure category. When the assessment identifies an existing installation that does not The repair scope for wind-damaged areas will bring those areas into current compliance — but owners also get information about non-damaged areas of the same roof that carry the same underlying risk.

Frequently asked questions