On a pitched shingle roof, wind damage usually means missing or creased shingles you can see from the street. On a flat or low-slope roof, the damage is often invisible from the ground. It shows up as a loose edge, a bubble in the membrane, or a seam that has started to open. Albuquerque has many flat roofs on homes, additions and commercial buildings, and spring winds and monsoon gusts test them every year.

How Wind Attacks a Flat Roof

Wind moving across a flat roof creates suction that pulls upward on the roof covering, strongest at the corners and along the edges. If the membrane isn't fully attached, or if the edge metal is loose, air gets underneath and lifts it. Once air is under the membrane, each gust works it looser.

Where Damage Starts

  • Edge metal and drip edge. Loose fasteners let wind get under the edge and peel it back, taking the membrane with it.
  • Coping and parapet caps. Coping that isn't secured to current standards can lift or blow off, leaving the top of the parapet open to water. See coping and edge metal.
  • Corners and perimeter seams. The highest uplift forces are here, so seams open here first.
  • Around rooftop equipment. Swamp coolers, HVAC units and vents create turbulence, and loose equipment can shift and tear the flashing around it.
  • Coatings. Windblown grit and debris scour roof coatings, and lifted coating can peel in sheets.

Signs to Look For After a Windstorm

  • A membrane that "breathes," billowing up and down in the wind
  • Bubbles or loose areas you can see from a ladder at the roof edge
  • Edge metal, coping or parapet caps that are bent, lifted or missing
  • Seams that look open, wrinkled or pulled apart
  • Pieces of membrane, metal or coating in the yard or gutters
  • New leaks or stains near exterior walls after the storm

Why small wind damage becomes big fast: a loose edge is an entry point for both air and water. The next gust lifts it farther, and the next rain runs under the membrane, where it can soak insulation and decking before a leak ever shows inside.

Membrane Types and Wind

  • TPO relies on its attachment to the deck and heat-welded seams. Well-installed TPO holds up well; problems usually start at a failed weld or a loose edge. See TPO roofing.
  • Modified bitumen can blister and lift at laps and edges as it ages.
  • Tar and gravel (built-up) roofs can lose gravel in high wind, exposing the layers beneath. See tar and gravel roofing.
  • Coatings depend on a sound surface underneath. Wind rarely removes a well-bonded coating, but it will peel coating from a failing substrate.

For a side-by-side comparison, see TPO vs. EPDM vs. modified bitumen.

Repair or Replace?

A loose edge, a few open seams or a lifted coping section can usually be repaired. If wind has lifted large areas of membrane, or water has already soaked the insulation underneath, replacement often makes more sense, because wet insulation keeps damaging the roof from below. A core cut or moisture survey shows how far water has spread.

New flat roofs can be built to resist wind better with proper attachment, secured edge metal and coping, and reinforced corners. See flat and low-slope systems and our wind damage repair page. If the storm also brought rain, check flat roof drainage too.