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Commercial Roof Inspection & Maintenance Guide

Protect Your Investment and Prevent Costly Damage 

 

Your commercial roof is one of your building’s most important features. Weather, aging materials, and lack of maintenance are the leading causes of leaks and damage. Left unaddressed, these issues can result in costly repairs, business disruption, or even premature roof replacement. 

This guide provides business and property owners with practical steps to identify most common causes of commercial roof leaks, conduct routine roof inspections, implement preventative maintenance to extend the service life of your roof, know when to hire a professional, and when it’s time to replace with a stronger roof.  

Common Causes of Commercial Roof Leaks 

Roof leaks in commercial buildings can be caused by a variety of factors. The most common include: 

  • Weather-Related Damage (Primary Cause) 
    • Heavy rain, snow, hail, high winds, and freeze/thaw cycles can weaken roofing materials over time. 
    • Severe weather often exposes or worsens existing vulnerabilities. 
    • Damaged Roof Membrane or Substrate (roof deck) – High foot traffic, mechanical equipment, flying debris, or aging materials can crack or puncture the roof’s protective layer, allowing water to seep in. 
  • Poor Drainage (Pooling Water) – Clogged gutters, blocked drains, ice dams, or improper slopes can lead to standing water that accelerates deterioration. 
  • Flashing & Sealant Failures – Flashing seals roof joints and penetrations like HVAC units, vents, and skylights. Loose, corroded, or deteriorating flashing and seals are common leak points. 
  • Aging Roof Systems – A roof may be considered “aged out” when repairs no longer solve recurring issues and the system is no longer performing as designed. Regular maintenance helps your roof last as long as possible. 
  • Improper Installation or Maintenance- Skipping preventive inspections, using low-quality materials, or improper installation techniques shorten roof lifespan and increase leak risks. 

 

Insurance & Roof Lifespan Considerations 

  • Coverage: Roof leaks may be covered by insurance if they result from a covered peril such as wind, hail, or fire, but not from wear and tear or lack of maintenance. The payout depends on your policy type (Actual Cash Value or Replacement Cost Value) and deductible, so always confirm coverage details with your insurance provider.   
  • Maintenance & Claims: Demonstrated and documented regular roof care and maintenance not only extends the life of your roof but also helps ensure claims are honored after severe weather. 

 

Commercial Roof Inspection and Preventive Maintenance 

  • Schedule a Professional Inspection at least once annually and before storm season. Many contractors offer annual service agreements as part of the roof warranty. Ask what type of inspection is provided (videos, photos, or on-site walk-through). 
  • Specialized Solar Panel Systems Inspections  
    • Ensure a licensed and insured photovoltaic contractor conducts routine maintenance throughout the year.  
    • Not every tenant or building owner owns the PV system, so establish clear maintenance agreements. Ownership structures may include:  
      • A tenant installing the system under a roof lease with the landlord’s permission. 
      • A landlord installing the system in exchange for a long-term tenant lease. 
      • A Power Purchase Agreement (PPA), where a solar developer owns and maintains the system. 
  • Hire professional services to safely remove accumulated snow and ice. Excessive buildup adds significant weight to the roof structure and can cause sagging or collapse.  Professional removal prevents damage to the membrane, flashing, and drainage systems that can occur if untrained personnel attempt removal. 
  • Maintenance 
    • Seal and repair cracks, gaps, and deteriorating seals around flashing, penetrations (vents, skylights, HVAC), and roof edges promptly. 
    • Keep the roof surface, drains, scuppers, gutters, and downspouts clear year-round. 
    • Maintain comprehensive records of all inspections, maintenance, and repairs, including photos and contractor reports for warranty and insurance purposes. 

 

How to Find & Address Roof Leaks 

  • Interior Inspection – Start here: 
    • Look for water stains, bubbling paint, damp insulation, or mold growth on ceilings and walls. 
    • Check attic spaces or mechanical rooms beneath the roof for moisture or water trails. 
    • Trace water paths upward to possible entry points on the roof surface. 
  • Ground-Level Observation – Walk around the building’s exterior and look for: 
    • Downspouts or gutters discharging improperly 
    • Water stains on exterior walls below roof lines 
    • Visible roof damage from below (missing shingles, loose flashing edges, etc.) 
  • On-the-Roof Inspection  

(Only if proper fall protection is available — otherwise, hire a professional.) 

    • Examine flashing, roof seams, and drainage systems for cracks, gaps, or clogs. 
    • Check for standing water, debris, and damaged membranes on flat roofs. 
    • Inspect around HVAC units, vents, skylights, and penetrations for deteriorating seals or visible gaps. 
  • Temporary Leak Containment – While awaiting permanent repairs: 
    • Move equipment, furniture, and inventory away from leaks. 
    • Use buckets or tarps to catch dripping water. 
    • Mark leak locations clearly for contractors. 

Important Note: These steps minimize damage but do not fix the source — schedule professional repairs promptly. 

Commercial Roof Inspection Checklist 

Every roof type requires specific inspection steps to ensure long-term performance. The following checklist outlines general inspection points and system-specific guidance for both low-slope/flat and steep-slope commercial roofs. 

Low–Slope/Flat Roof Systems 

Low-slope/flat roofs are common on commercial buildings and require close monitoring because standing water, debris buildup, and membrane aging can lead to significant leaks and structural damage over time. 

General Inspection Steps: 

  • Look for long-term standing water or ponding. Signs include mold growth, vegetation, staining, or algae on the surface. 
  • Inspect for membrane deterioration: cracks, splits, brittleness, fading, or blistering.  
  • Clear any debris such as leaves, sticks, needles, and dirt that could block drainage points or cause punctures. 
  • Check the underside of the roof or drop ceiling for water stains or mold. 

Roof Cover System-Specific Checks:   

Ballasted Roof System (Stone Ballast) 

  • Ensure stone ballast is evenly distributed; cover any bare membrane spots immediately. 
  • Avoid dragging rocks, which could tear or puncture the membrane. 
  • After storms or high winds, check for displaced stones and inspect for membrane damage. 
  • Confirm ballast blocks (for panels or equipment) are anchored, strapped, or bolted together. Not recommended in hurricane-prone areas. 
  • Confirm parapet walls, perimeter flashings, and drainage points are not blocked by ballast movement. 

 

Built-Up & Modified Bitumen Roofs 

  • Monitor for bubbles, blisters, cracks, or tears, especially near seams and connections.  
  • Check for loss of embedded gravel or smooth surface coatings that protect the roof from UV degradation.  
  • Inspect all seam connections and flashing edges for excessive wear or gaps.  

 

Single-Ply Membrane Roofs (e.g., TPO, EPDM, PVC) 

  • Inspect for open/worn seams, lifting edges, or gaps. 
  • Check for tears, punctures, fasteners backing out, or areas where the membrane has shrunk or pulled away.  
  • Look for brittleness or cracking from UV exposure.  

 

Sprayed Polyurethane Foam (SPF) Roofs 

  • Check for signs of damage in the foam such as excessive weathering, cracking, punctures, or areas that look worn down. 
  • Inspect the protective top coating (often acrylic or elastomeric)., If the coating looks thin, worn, missing, the foam underneath can be damaged by sunlight (UV rays).  

 

Metal Panel Roofs 

  • Check for loose or missing screws, deteriorated rubber washers, and corroded fasteners.  
  • Inspect for rust spots, paint wear, dents, or divots that may indicate hail or wind damage.    
  • Verify panel seams remain tight and sealed. 

 

Additional Low-Slope Inspection Best Practices:  

Drainage Systems  

  • Clear debris like leaves, sticks, construction materials, dirt, and granules from interior roof drains, gutters, scuppers, and downspouts to prevent blockages during storms. 
  • Look for long-term ponding in gutters or drains. If no debris is present but water remains, verify gutters are properly sloped towards downspouts. 
  • Inspect gutters for missing, loose, or disconnected sections. Ensure gutters are securely anchored to the building with straps designed to withstand high winds. 

Metal Edge Flashing  

Metal edge flashing is the leading cause of roof cover failure in high winds; if it’s not properly secured, it can trigger roof cover loss, water intrusion, and costly business disruption. 

  • Inspect perimeter flashing for looseness, gaps or damage.  

Roof-Mounted Equipment  

Roof-mounted equipment such as HVAC units, exhaust fans, and stacks are common sources of leaks and wind-related failures. 

  • Check curbs for signs of leaks, gaps, deterioration. If water intrusion is suspected, check the curb for rot, and repair as needed. Verify flashing around equipment curbs is secure and intact. 
  • Inspect all metal components, including panels, screws, flashing on and around curbs for rust or wear. 
  • Ensure equipment is tightly strapped, bolted, or anchored to withstand high winds. Test straps and cables by gently pulling on all securing straps and cables to ensure they are tightly fastened, with little to no slack. Review manufacturer guidelines for proper attachment. 
  • After maintenance work, confirm all screws, straps, and cables are tightened, debris is cleared, and flashing is resealed if disturbed. 
  • Remove debris: Clear debris from around and beneath equipment to prevent water ponding. 

Solar Panels  

Solar panels and arrays that fail or become detached can cause extensive damage to roofs, weakening a building’s protection against severe weather. Once detached, they can become flying debris. 

  • Confirm panels and hardware are secure to the racking system.  
  • For ballasted arrays, verify blocks are anchored/strapped. (Not recommended in hurricane-prone areas.)   

Lightning Protection  

If a metal conductor cable comes loose during high winds, it can drag or slam against the roof membrane, causing serious damage.  

  • Test rods and cables by gently pulling on the securements and conductor poles; there should be little to no slack.  
  • Replace old connectors with closed-loop types (rather than a 3-prong connector). 

Roof Hatches  

  • Check bolts, nuts, and screws for tightness. Inspect hatch flashing for cracks or leaks. 

Skylights  

  • Inspect for cracks, leaks, or hail damage. Check attachments to curbs and address rotting wood. Look for signs of hail damage. 

Steep–Slope Roof Systems 

Although less common in commercial buildings, steep-slope roof systems still require periodic inspection at least once a year and after major storms. 

Roof Cover System-Specific Checks: 

Asphalt Shingles 

  • Inspect for loose, curling, torn, or missing shingles. 
  • Check for granule loss exposing underlying materials to UV damage. 

Clay & Concrete Tiles 

  • Look for cracked, broken, missing, or detached tiles that could allow water to seep in. 
  • Inspect flashing at tile edges and ridges for deterioration.  

Metal Panels 

  • Inspect for loose screws, corroded fasteners, rust spots, dents, or worn paint finishes.  
  • Confirm panel edges and seams remain sealed and secure.  

 

Additional Steep-Slope Inspection Best Practices:  

Vents, Skylights & Chimneys 

  • Vents: Check for loose seals, rusted, or deteriorated parts. 
  • Skylights: Inspect for cracks, water intrusion, and loose or wavy flashing. 
  • Chimneys: Check flashing for gaps or leaks and confirm mortar is intact. 

Roof Valleys & Seams 

  • Inspect valley seams and dormer connections for leaks. 
  • Remove debris such as leaves, branches, or dirt that collect in valleys and restrict drainage. 

Gutters & Downspouts 

  • Inspect gutters for missing, loose, or disconnected sections. Ensure gutters are securely anchored to the building with straps designed to withstand high winds. 
  • Remove all debris, vegetation, and granules. 
  • Confirm downspouts divert water at least 3 feet away from the foundation. 

 

 

Building Stronger: Want to Build a Better Commercial Roof? 

 

Get a FORTIFIED Commercial Roof™—a construction standard and designation program developed by the Insurance Institute for Business & Home Safety (IBHS), a nonprofit dedicated to reducing severe weather damage and preventing avoidable business disruption and financial loss. 

 

Learn More about Commercial or Multifamily resilient roof options and more.