Inspection Guide
A commercial roof inspection is only as valuable as the documentation it produces. We review hundreds of inspection reports each year on behalf of building owners, and the difference between a report that protects an asset and one that wastes a service visit comes down to scope, evidence, and how findings tie back to capital decisions. A walk that ends in a vague recommendation to "monitor" or "budget for replacement" tells you nothing actionable. This guide outlines what a competent inspection should cover, what the deliverable should contain, and how to read it as an owner deciding where roofing dollars go.
Establish the system and its history first
Before anyone steps onto the roof, the inspection should establish what is actually up there. Membrane type drives everything that follows, and a TPO field behaves nothing like an EPDM ballasted system or a four-ply built-up roof with gravel surfacing. The inspector should confirm the system, attachment method (mechanically fastened, fully adhered, or ballasted), approximate age, and whether prior recover layers exist. Many roofs carry two or even three membranes stacked over the original deck, which has direct consequences for load, future tear-off cost, and code compliance.
The report should also reconcile what is found against any warranty on file. A manufacturer's no-dollar-limit warranty on a PVC or TPO system has specific conditions around penetrations, repairs, and ponding, and an inspection is the moment to flag activity that could void coverage. If we do not know the warranty terms going into the inspection, we are inspecting blind to one of the largest sources of financial exposure on the asset.
The membrane field and seams
The bulk of inspection time belongs to the field of the membrane and the seams that hold it together. Seam failure is the most common path to interior water entry on single-ply roofs, and a good inspector probes seams rather than glancing at them. On a thermoplastic system this means checking for separation, fishmouths, and the brittleness that signals a hot-air weld nearing the end of its service life. On EPDM, it means examining lap adhesive and seam tape for the edge peel that precedes a leak.
A thorough field inspection documents the following at minimum:
- Membrane surface condition, including chalking, crazing, granule loss on modified bitumen, and UV degradation
- Seam integrity tested by probe, with photos of any separation or voids
- Punctures, abrasions, and traffic damage, particularly along service paths to rooftop units
- Blisters, ridging, and signs of trapped moisture or substrate delamination
- Membrane shrinkage pulling at perimeters and penetrations, common on aging EPDM
- Condition of any cover board or insulation that is exposed or accessible
Flashings, penetrations, and the perimeter
Most leaks do not originate in the open field. They originate at the transitions, which is why flashing and penetration detail deserves disproportionate scrutiny. The inspector should examine base flashings at walls and curbs, counterflashing and termination bars, pipe boots, drain bowls, scuppers, and the sealant at every penetration. Pitch pans filled with hardened, cracked mastic are a recurring finding and a recurring source of water entry. Rooftop HVAC curbs are another, particularly where condensate lines and gas piping breach the membrane without proper flashing.
The perimeter and edge metal carry both a waterproofing and a wind-uplift function. Loose or under-fastened edge metal is a code and insurance concern because perimeter failure during a wind event can peel a membrane progressively across the field. The report should note coping condition, fastening, and any gaps at metal joints.
Drainage and ponding
Drainage is where a roof's design and a roof's reality often diverge. The inspection should map where water actually goes, not where it was supposed to go. Standing water that remains more than 48 hours after rain accelerates membrane aging, voids many warranties, and signals deck deflection or clogged drainage. We want the report to identify ponding locations, drain and scupper condition, debris accumulation, and whether interior drains are pulling properly. Photographs of ponding outlines, ideally with stain rings showing recurring depth, are far more useful than a single line noting that ponding exists.
What the deliverable must contain
An inspection that lives only in the inspector's head is worthless to an owner six months later. The written deliverable is the asset. It should give you enough to act, defend a warranty claim, and brief a board or asset manager without a follow-up call. We expect every inspection report to include:
- A roof plan or diagram with findings located by area, not just a list of observations
- Date-stamped photographs tied to each significant finding
- A condition rating that distinguishes active leaks from deferred-maintenance items from end-of-life indicators
- Prioritized recommendations separating immediate repairs from planned capital work
- An estimate of remaining service life with the reasoning behind it
- Moisture survey results where infrared or capacitance scanning was warranted
For owners managing a portfolio, that structure also makes findings comparable across buildings, which is what turns individual inspections into a capital plan.
How to read the report as an owner
When we review a report for a client, we are reading for decision triggers, not adjectives. The questions that matter are whether any finding threatens occupancy or inventory, whether any condition is actively voiding warranty coverage, whether deferring a repair this year materially raises next year's cost, and whether the remaining service life justifies restoration spending or argues for letting the roof run to replacement. A report that lets you answer those four questions has done its job. One that leaves you guessing has cost you a service visit and given you nothing to defend a capital request with.