Commercial roofs almost never fail all at once. They fail at a clogged drain, a lifted lap, a curb flashing that somebody stepped on — small things that were visible for two years before the ceiling tile stained. A twice-yearly walk catches nearly all of it.
Here’s the checklist we use, section by section, plus what to document so a warranty claim actually holds up.
Quick answer
How often to inspect — and when
Twice a year, at the two times of year that tell you the most:
- Spring — the damage assessment. Freeze-thaw cycling, ice loading, and snow removal all leave marks. This is when you find split seams, crushed insulation, and punctures from winter work.
- Fall — the preparation pass. Clear drains before leaves fall, close up open details, and fix anything you don’t want to discover in January. In Chicagoland this is the visit that matters most.
- After any major weather event — high wind, hail, or heavy snow. Same NRCA recommendation, and it’s also the window in which storm damage is easiest to attribute to the storm.
Some roofs earn a quarterly schedule: buildings with heavy rooftop equipment, frequent trade access, restaurant or industrial exhaust, or a membrane past about 15 years. If HVAC techs are on your roof monthly, inspect like it.
Commercial roofs don't fail from neglect all at once. They fail at one clogged drain that nobody wrote down.
1. Drainage — start here every time
Standing water shortens membrane life, loads the structure, and finds every marginal seam on the roof. Drainage is the highest-value ten minutes of the whole inspection.
- Clear all drains, strainers, and baskets — leaves, sediment, ballast, packaging debris.
- Check scuppers and overflow scuppers for blockage and for cracked or separated sheet metal.
- Look for ponding — water still sitting more than 48 hours after rain, or the tell-tale dirt rings and biological growth where it sat.
- Check for dished or spongy insulation around drains, which signals saturation.
- Inspect gutters, downspouts, and internal leaders for blockage and separation. Where a building has exterior collection, our gutter work ties directly into this.
- Note any new low spots compared to the last visit — deck deflection is a structural conversation, not a roofing one.
Some roofs earn a quarterly schedule: buildings with heavy rooftop equipment, frequent trade access, restaurant or industrial exhaust, or a membrane past about 15 years. If HVAC techs are on your roof monthly, inspect like it.
2. Membrane field and seams
On a single-ply roof, the seams are the roof. The field of the sheet rarely leaks on its own.
- Walk every seam and lap. Look for lifted edges, fishmouths, and any spot where the lap edge isn’t tight.
- Check for punctures, cuts, and abrasion — most cluster along the walking routes between the roof hatch and the equipment.
- Look for crazing, chalking, or brittleness in the membrane surface, which means the UV package is spent.
- On TPO and PVC, note discoloration or shrinkage pulling at terminations.
- On EPDM, check for shrinkage tension at corners and curbs.
- On modified bitumen, look for blisters, ridging, and open laps; check granule loss on cap sheets.
- Press for soft spots underfoot — that’s wet insulation, and it doesn’t dry out by itself.
If you’re on TPO specifically, the failure pattern and its timeline are worth knowing in detail — we cover it in how long a TPO roof lasts.
3. Flashings and penetrations
This is where the leaks are. Every hole in a roof is a detail somebody had to build, and details are where corners get cut.
- Pipe boots and pitch pans — cracked boots, clamps backed off, pitch pockets shrunk or dried out.
- Curb flashings at HVAC units, exhaust fans, and skylights — check the corners specifically; that’s where they open.
- Drain flashings and clamping rings — loose bolts, deteriorated sealant.
- Chimney and wall counterflashing — verify it’s let into the wall or under the cladding, not surface-caulked. A caulked termination is a maintenance item pretending to be a flashing.
- Expansion joints — torn covers, failed bellows.
- Conduit, gas lines, and cable runs — anything resting directly on the membrane is wearing a hole in it. Get it on blocks or sleepers.
- Abandoned penetrations — old curbs and pipes left in place after equipment changes. These leak for years.
When one of these needs replacing, the part should fit the opening — not the other way around. We fabricate our own pipe flashings, collector boxes, scuppers, and curb metal in-house, formed to the actual penetration rather than adapted from stock pieces. No generic parts, no shortcuts.
4. Perimeter and edge metal
Wind damage starts at the edge. Almost always.
- Coping and fascia metal — loose sections, open joints, missing fasteners, oil-canning.
- Gravel stops and drip edge — separation at splices
- Termination bars — backed-out fasteners, deteriorated sealant along the top edge.
- Parapet walls — cracked masonry, failed tuckpointing, open mortar joints. Water entering a parapet shows up inside as a “roof leak” that isn’t.
- Base flashings at wall junctions — verify height and attachment.
- Corners — the highest uplift pressure on the roof is at the corners, so inspect them hardest.
5. Rooftop equipment and foot traffic
- Walk pads — present, intact, and actually running where people walk. Add them where you can see a worn path.
- Condensate lines — discharging to a drain, not onto the membrane. A dripping condensate line will eat a hole in a roof over a season.
- Equipment leaks — refrigerant oil, grease from kitchen exhaust, and hydraulic fluid all degrade single-ply membrane. Grease near a restaurant exhaust fan is a membrane emergency, not a cleaning issue.
- Equipment mounts and curbs — rust, movement, missing fasteners.
- Debris — tools, screws, banding, and packaging left behind by trades. A single dropped screw under a boot becomes a puncture.
- Access control — know who’s been on the roof. Most punctures are made by people who don’t work on roofs.
6. Inside the building
Half of a roof inspection happens indoors, and it’s the half that gets skipped.
- Ceiling tiles and drywall — stains, sagging, discoloration. Photograph and date them so you can tell an old stain from a new one next visit.
- Deck underside where visible — rust on steel deck, water tracking, delamination on wood.
- Insulation — sagging or discolored batts in accessible areas.
- Around penetrations — the inside face of curbs, pipes, and skylights.
- Tenant reports — collect them. A tenant’s “there was a drip in March” is data.
7. Records and warranty compliance
This is the section that saves money, and it’s the one property managers most often lose on.
- Photograph every visit — same vantage points each time, so you can compare year over year.
- Write a dated report for each inspection listing what was found, what was fixed that day, and what’s outstanding.
- Log all roof access — who went up, when, and why.
- Keep the warranty documents accessible and read the maintenance obligations in them. Most commercial roofing warranties carry maintenance and documentation requirements, and a claim on an undocumented roof is a hard claim to win.
- Use the same contractor for repairs where the warranty requires it — unauthorized work can void coverage.
- Fix the small items during the inspection visit. A resealed pitch pan costs a fraction of the interior repair it prevents.
Need a documented inspection on your commercial roof?
We walk the roof, photograph the findings, fix the small items on the spot, and hand you a written report — no upsells.