A closer look at low-slope decking near Portsmouth revealed a challenge many Tidewater property owners face every storm season: severe ponding water​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​. In this episode of Roofing for Reel, we took a trip out to a local commercial site where the building's flat roof was struggling to shed heavy rainwater​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​. Low-slope roofs don't have the steep pitch of standard asphalt shingle roofs, so when drainage outlets or sloped insulation aren't perfectly aligned, water pools in place long after the storm passes​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​. When The Roofing Company, Inc. team originally inspected this Portsmouth roof, standing water sat across the surface like a backyard swimming pool​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​.

The Problem

Standing water on a commercial or flat roof isn't just an unsightly mess—it's a ticking clock for structural issues . In the roofing industry, water that sits on a flat membrane for more than 48 hours is called "ponding water." That constant, heavy pressure forces moisture against roof seams and edge flashings (the metal strips that seal roof edges and perimeter walls) . Over time, standard adhesives break down under the weight, causing slow leaks, weakening the underlying roof deck, and giving property owners unnecessary stress during every midnight downpour .

The Technical Why

To eliminate this persistent water issue and restore total peace of mind, The Roofing Company team installed a specialized Fibertite single-ply roofing system . Here is how the mechanics work to protect the building:

  • Engineered Membrane: Fibertite utilizes a high-density base fabric coated with a thermoplastic blend specifically formulated to withstand continuous water contact and UV exposure without degrading .

  • Hot-Air Welded Seams: Instead of using glue or seam tape that eventually weakens under standing water, the overlapping seams are fused together using hot air to create one continuous, watertight barrier.

  • Sealed Wall Scuppers: We fully wrapped and sealed the wall scuppers—the square drainage openings along the perimeter parapet walls—so water drains freely off the roof without seeping behind the structure .

When we checked back on this Portsmouth property following a heavy coastal rainstorm, the entire roof deck was completely dry with zero ponding water .

Professional Advice

If your commercial building or residential property features a low-slope roof, porch deck, or flat transition, here are a few simple ways to protect your investment:

  • Clear Perimeter Drains and Scuppers: Routinely clear away leaves, pine needles, and storm debris that block drainage scuppers and downspouts.

  • Inspect Flashings After Storms: Keep an eye on wall flashings and roof edges for any signs of lifting or seam separation where standing water accumulates.

  • Select Water-Resistant Materials: Standard roofing materials degrade quickly under standing water, so choose low-slope systems explicitly engineered to handle ponding conditions .

Whenever you're ready to take a closer look at your roof's drainage or need an honest second opinion after a storm, give us a shout at 757-867-6600 or fill out the form on this page.