10 Signs Your Commercial Flat Roof Needs Repair


Did you know that nearly 50% of commercial building owners have to deal with flat roof issues within the first decade of installation? Ignoring these problems can lead to severe consequences, from structural damage to heightened operational costs. Regular maintenance is essential for extending the lifespan of your commercial flat roofing. By recognizing early warning signs, you can prevent minor issues from escalating into costly repairs or complete replacements. This post will walk you through 10 crucial signs indicating that your flat roof needs immediate attention.

Sign 1: Water Pooling


Water pooling, also known as ponding, occurs when water remains on the roof surface for more than 48 hours after precipitation. This is a common issue for flat roof types since they lack the natural slope for water runoff.


The dangers of water pooling include:

  • Structural damage due to prolonged moisture exposure
  • Increased risk of leaks
  • Mold and mildew growth affecting indoor air quality


Addressing water pooling involves:

  • Slope correction: Adjust the roof’s pitch to direct water toward drains
  • Installing additional drainage systems: Ensure efficient water removal

Table: Pros and Cons of Slope Correction



Effective water diversion

Can be expensive to implement

Reduces long-term damage

May require structural adjustments

Sign 2: Blistering and Bubbling


Blistering and bubbling occur when trapped moisture or air within the flat roof materials expands due to temperature changes, creating raised sections on the roof membrane.


  • Compromised insulation effectiveness
  • Increased vulnerability to leaks


  • Patching or replacing affected sections
  • Improving roof ventilation to reduce internal moisture

List: Causes of Blistering and Bubbling

  • Poor initial flat roof installation
  • Moisture trapped beneath the membrane
  • Extreme temperature fluctuations

Sign 3: Cracks and Splits in the Membrane


Cracks and splits are common in aging roofs or those exposed to severe weather conditions, particularly UV radiation and thermal expansion/contraction.


  • Water seepage leading to interior damage
  • Degradation of insulation properties


  • Sealing cracks with waterproof coatings


  • Replacing sections with severe damage

Table: Common Causes of Cracks and Splits



UV Exposure

Sunlight deteriorates the roofing membrane over time

Temperature Changes

Thermal expansion and contraction cause stress and eventual cracking

Poor Installation

Subpar materials or techniques result in early wear and tear

Sign 4: Membrane Shrinkage


Membrane shrinkage happens over time as certain flat roof materials contract, pulling away from edges and joints, especially in single-ply systems like EPDM.


  • Creation of gaps and leaks
  • Damage to flashing and roof edges


  • Reinforcing affected areas with additional materials
  • Complete membrane replacement if shrinkage is extensive

Sign 5: Sagging Roof


A sagging roof indicates underlying structural issues, often due to long-term water damage or insufficient support during the original commercial roof installation.


  • Risk of roof collapse
  • Water accumulation, leading to further damage


  • Reinforcing the roof’s structure
  • Correcting the slope to ensure proper drainage

List: Structural Reinforcement Methods

  • Adding support beams or trusses
  • Using lightweight, high-strength materials

Sign 6: Increased Energy Bills


Significantly higher energy bills may indicate a loss of thermal efficiency due to compromised roof insulation.


  • Higher operational costs
  • Increased indoor temperature fluctuations


  • Inspecting and improving roof insulation
  • Applying reflective coatings to reduce heat absorption

Sign 7: Interior Water Damage


Leaks from a damaged commercial flat roof often manifest as visible damage inside the building, such as stained ceilings and walls.


  • Potential mold growth affecting health
  • Damage to interior fixtures and equipment


Table: Common Signs of Interior Water Damage



Ceiling Stains

Brown or yellow marks on the ceiling

Peeling Paint

Moisture causing paint to bubble and peel

Sign 8: Visible Roof Debris and Deterioration


Loose granules, torn membranes, or degraded flat roof materials are signs of wear and tear that need immediate attention.


  • Clogged drains, leading to water pooling


  • Accelerated roof degradation


  • Regular cleaning and inspection
  • Replacing or repairing deteriorated materials

Sign 9: Visible Rust


Rust formation on roof components like metal decking and HVAC units indicates prolonged exposure to moisture, often due to leaks.


  • Compromised structural integrity
  • Increased likelihood of leaks


  • Treating rust with anti-corrosive solutions
  • Protecting metal surfaces with coatings

Sign 10: Unpleasant Odors Indoors


Mold and mildew thrive in damp environments, creating musty odors that permeate the building.


  • Health risks for occupants
  • Loss of building appeal and aesthetics


  • Identifying and repairing leaks
  • Improving ventilation to reduce moisture buildup


Regular maintenance and prompt action are key to prolonging the life of your commercial flat roofing. By recognizing these 10 signs, you can prevent minor issues from turning into costly repairs. If you notice any of these warning signs, consider reaching out to a professional roofing company like J.R. Swigart Roofing for a thorough inspection and repair.


Don’t wait until it’s too late! Schedule your regular roof inspections today and contact J.R. Swigart Roofing for expert advice and services.

Resource Link

For more information on maintaining your commercial flat roofing, check out our maintenance checklist and visit our roofing solutions page.

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