Storm Damage: What to Expect

September 17, 2019

The weather can provide a real lashing to your roof(s). If it looks like Mother Nature is about to unleash the fury, be aware of the potential damage. We’ve got a list of conditions and the destruction to roof elements, roof membrane, and the entire roofing system that could result.

High winds

Membrane Damage

During high winds, rooftop unit hoods, tree limbs, debris, and obsolete equipment can be forced from its location and pushed across the roof membrane causing punctures, tears, and abrasions.

Dislodged Roof Elements

Roof vents and roof hoods can become unsecured. Leaks are likely to result. If completely dislodged, expect damage to the roof membrane as the wind blows unsecured roof projections across the field of the roof.

Edge Metal Damage

Gutters or metal and membrane at the roof’s edge can be compromised or damaged. Wind uplift pressure is greatest along the edges and corners; if the integrity of the roof edge is compromised, leaks are likely and roof blow-off is possible.

Blow-Off

What starts as a small opening allowing wind to penetrate, can have catastrophic results. The entire roof, including the roof deck, can blow off during tropical storms or tornadoes.

Hail

Widespread Damage

Unlike the destruction caused by windborne debris, which is isolated to a specific area, hail damage can cover the entire roof. A D. C. Taylor Co. assessment of a hail-damaged shopping center roof revealed more than 200 punctures in a 100-square-foot area.

Punctures

Punctures or splits, and subsequently, leaks are the most apparent damage single-ply membranes suffer from hail. Damage to the roofing membrane is especially problematic at the fastener in the membrane seam.

Damaged Insulation

Hail of a significant size hitting with a large enough force will damage the insulation layer of a roofing system. Physical damage may be sustained to the interface of the insulation and the insulation facer. Additionally, potential moisture damage can reduce insulation’s efficiency and the physical breakdown of the foam cell structure.

Broken Skylights

Hail that exceeds the impact resistance of skylight structures will cause them to crack. Skylight screens can help prevent hail damage.

Heavy (or Long Periods of) Rain

Leaks

Whatever the cause of a roof leak (e.g. sealants that have dried out, an older roof membrane that succumbs to drastic temperature swings, lack of maintenance, etc.), if you didn’t notice it before, you will during periods of heavy rain.

Be leery of roof leaks that appear during or after a storm that delivers both substantial rain and strong winds; the roofing system may not be to blame for your water woes. Even the best weatherproofing around doors and windows can be tested. It’s easy to mistake water coming in around an upper-story window, skylight, or roof access door as a roof leak.

Ponding Water

Ponding water can become a problem in heavy rainfall if you have an inadequate drain sump. It can also be the result of drains and gutters clogged with debris deposited by the storm. Water that remains on the roof for more than 48 hours is a concern.

Roof Collapse

Too much water compromises structural integrity. Water that doesn’t drain adds weight to the roof that structural members and the roof deck may not have been designed to hold; it could result in roof collapse.

Suspect you have storm damage and aren’t sure what to do about it? Read this blog for some helpful tips and advice!