A summer hailstorm can move through the Greater Toronto Area in twenty minutes and leave behind six figures of damage on a commercial roof that nobody notices for weeks. Unlike a residential shingle roof, where cracked or missing shingles are obvious from the driveway, a low-slope commercial membrane can absorb serious impact damage while looking almost untouched from ground level. Property managers who wait for a leak to appear are often looking at a much larger repair bill than they would have faced with a prompt inspection.

These are the essential tips for commercial roof hail damage repair that every building owner, facilities manager, and property management company in the Toronto region needs to understand before the next severe weather event rolls through. We have compiled this guide from years of emergency call-outs, insurance claim inspections, and full membrane replacements across office parks, retail plazas, warehouses, and multi-unit buildings throughout the GTA.

Getting commercial roof hail damage repair right requires a different playbook than residential work. The membranes, insulation systems, drainage configurations, and rooftop equipment on a typical commercial building all respond to hail impact differently than asphalt shingles, and the financial stakes of missing damage are considerably higher. Below we walk through the four essential tips in detail, along with the supporting information you need to manage a claim, choose the right materials, and avoid the mistakes that turn a manageable repair into a full re-roof.

Why Commercial Roofs Are So Vulnerable to Hail

Most commercial buildings in Toronto, Mississauga, and the surrounding suburbs use a low-slope or flat roofing system rather than pitched shingles. These systems include TPO, EPDM rubber membrane, modified bitumen, and built-up asphalt roofing. Each of these materials has a very different hail tolerance, and each hides damage in a different way.

Hail striking a low-slope membrane compresses the surface against the insulation board beneath it. On EPDM, this often shows up as small circular indentations or bruising that is difficult to see without close inspection. On TPO and modified bitumen, hail impact can crack the surface granules or top ply without immediately breaching the waterproofing layer, meaning water intrusion may not begin for months. Built-up roofing can suffer aggregate displacement, exposing the felt plies underneath to UV degradation and eventual failure.

The insulation board beneath the membrane is just as important as the surface layer. Repeated hail impact can crush polyisocyanurate insulation, creating soft spots that compromise the roof’s structural integrity even when the membrane itself is intact. This is one of the main reasons a full roof repair assessment after a storm needs to go beyond a visual walk of the surface and include core sampling or moisture scanning in suspect areas.

Rooftop equipment adds another layer of risk. HVAC units, exhaust fans, skylights, drains, and flashing details are all more vulnerable to hail impact than the flat membrane field itself. Bent fins on condenser coils, cracked skylights, and dented flashing collars are common findings after a hailstorm and are frequently overlooked during a rushed inspection.

Tip One: Document Everything Before You Touch the Roof

The single most important step in commercial roof hail damage repair is thorough documentation before any cleanup or repair work begins. Insurance adjusters need to see the roof in the condition the storm left it, and once debris is cleared or temporary patches are applied, that evidence is gone.

Photograph and video the entire roof surface, including wide establishing shots and close-up detail images of every impact mark, bruise, crack, or displaced material. Include a tape measure or coin in close-up photos for scale. Photograph all rooftop equipment separately, since HVAC and mechanical damage is often claimed under a different line item than the roof membrane itself.

Record the storm date and, if possible, corroborating weather data from Environment Canada or a local weather station. Insurance companies frequently dispute the timing of hail damage on flat roofs because the damage is not always immediately visible, so having a documented storm date tied to your inspection report strengthens the claim considerably.

Keep a written log of every person who accesses the roof after the storm, including contractors, adjusters, and maintenance staff, along with the date and purpose of each visit. This chain-of-custody record matters more than most property managers realize when a claim is disputed later.

Tip Two: Get a Professional Inspection Within 48 Hours

Hail damage on a commercial membrane is genuinely difficult to identify without training and the right tools. A qualified inspector uses a combination of visual assessment, core sampling, and infrared moisture scanning to find damage that is invisible from a casual walk-through.

Core sampling involves cutting a small, circular section out of the membrane and insulation in a suspect area to examine the internal layers. This tells the inspector whether the insulation board has been crushed, whether the membrane has separated from the substrate, and how many plies of material are present, which matters for both the repair plan and the insurance estimate.

Infrared thermography is used to scan the roof for trapped moisture that has already begun infiltrating through hairline cracks invisible to the naked eye. Because wet insulation reads a different surface temperature than dry insulation once the sun goes down, an infrared scan performed at dusk can map out water intrusion across the entire roof deck in under an hour. This step alone often reveals that hail damage is more widespread than the visible impact marks suggest.

Timing matters. Booking an inspection within 48 hours of a storm keeps your documentation credible, gets ahead of secondary water damage, and often speeds up insurance approval because adjusters can schedule their own site visit while the damage is still fresh. Waiting weeks to call a contractor is one of the most common reasons commercial hail claims get denied or reduced.

Tip Three: Choose the Right Repair Method for Your Membrane Type

Not every hail-damaged commercial roof needs a full roof replacement. In many cases, targeted repairs to the affected sections restore the roof’s waterproofing without the cost and disruption of tearing off the entire system. The right method depends heavily on the existing membrane type, the extent of the damage, and the remaining service life of the roof.

EPDM rubber membranes with isolated bruising or small punctures can often be patched using liquid-applied seam tape or cured EPDM patches bonded with membrane-specific adhesive. TPO roofs with cracked granules or minor punctures are typically repaired with heat-welded patches that fuse directly to the existing membrane, creating a bond as strong as the original seam. Modified bitumen roofs with granule loss or surface cracking usually require a torch-applied or cold-adhesive patch layered over the damaged section, sometimes combined with a protective granule coating to restore UV resistance.

When hail damage is widespread across the field of the roof rather than isolated to a few spots, or when core samples reveal crushed insulation across large areas, patch repairs are no longer cost-effective. At that point a full flat roofing system replacement becomes the more sensible long-term investment, since patching a roof with pervasive hidden damage tends to produce recurring leaks within a year or two.

Building owners should also budget time for how long each approach takes, since a patch repair completed in a day is very different from a multi-week tear-off and replacement, especially for a building that cannot easily close sections for construction.

Tip Four: Work With Your Insurance Adjuster Strategically

Commercial hail claims are frequently underpaid on the first offer, not necessarily because of bad faith but because adjusters handling dozens of claims after a regional storm rarely have time for a detailed roof-specific inspection. Having your own roofing contractor present during the adjuster’s site visit changes the outcome significantly.

A contractor who specializes in commercial roofing can point out damage the adjuster’s general inspection might miss, such as insulation crushing that only shows up on a core sample, or flashing damage around rooftop units that gets overlooked in a quick walkthrough. This collaborative approach, sometimes called a joint inspection, tends to produce a more accurate and complete damage estimate than either party working separately.

Request a written scope of work from your contractor before the adjuster meeting, itemizing every affected component: membrane, insulation, flashing, drains, rooftop equipment, and any interior damage from leaks that occurred before repairs began. Compare this scope against the adjuster’s estimate line by line rather than accepting a lump-sum settlement figure. If the two documents diverge significantly, request a re-inspection or invoke your policy’s appraisal clause rather than settling for less than the repair actually requires.

Keep detailed records of every communication with your insurer, including names, dates, and summaries of phone calls. Commercial policies often have strict deadlines for filing supplemental claims if additional damage is discovered during repair work, so staying organized from day one protects your ability to recover the full cost of repairs later.

Preventing Future Hail Damage and Extending Roof Life

While no commercial roof coating makes a membrane completely hail-proof, several upgrades meaningfully reduce the severity of future storm damage. Impact-resistant membrane products, rated under UL 2218 for impact resistance, use thicker or reinforced top plies that resist puncture and bruising far better than standard membranes. For buildings replacing an ageing roof, specifying an impact-rated membrane is a worthwhile upgrade given how frequently the GTA experiences severe summer storms.

Regular roof maintenance also plays a significant role in storm resilience. A roof with clogged drains, ponding water, or already-deteriorated seams sustains far more damage from a given hailstorm than a well-maintained roof of the same age and material. Scheduling a maintenance inspection each spring, before severe weather season begins, and again each fall catches small issues before they become storm-damage multipliers.

Attic and roof deck ventilation also affects how a roof handles the aftermath of hail damage. Poor ventilation traps moisture that has infiltrated through hairline cracks, accelerating insulation degradation and mould growth. Buildings with older or undersized attic ventilation systems should have this reviewed at the same time as any hail damage assessment, since the two issues often compound each other.

Common Mistakes That Turn a Repair Into a Full Replacement

Several avoidable mistakes routinely escalate the cost of commercial roof hail damage repair. The most damaging is delay: waiting to schedule an inspection allows minor breaches to become saturated insulation and interior leaks, at which point patch repair is no longer sufficient and the building owner is looking at a full replacement instead.

Another common error is hiring a general contractor without commercial roofing specialization for the repair work. Residential roofers are highly skilled at shingle and steep-slope work, but low-slope commercial membranes require different tools, adhesives, and welding techniques. A patch improperly bonded to a TPO or EPDM membrane frequently fails within a single season, forcing the building owner to pay for the same repair twice.

Skipping the insulation assessment is another frequent misstep. Building owners sometimes accept a quote for membrane patching alone, only to discover months later that crushed insulation beneath the patch is still allowing water to track laterally under the membrane and emerge in a completely different part of the building. A proper commercial roof hail damage repair always evaluates the insulation layer, not just the visible surface.

Finally, many property managers underestimate how quickly Toronto’s freeze-thaw cycle can worsen unrepaired hail damage once the seasons turn. A crack that seems minor in July can widen dramatically after repeated freezing and thawing through a Toronto winter, turning a small autumn repair job into an emergency mid-winter leak. Addressing hail damage during the summer and early fall, while weather conditions are favourable for membrane work, avoids this seasonal compounding entirely.

What a Thorough Commercial Roof Hail Inspection Should Include

Property managers evaluating contractor proposals should expect a hail damage inspection to cover the full roof system, not just a quick visual pass. A complete inspection typically includes a walk of the entire membrane field noting every visible impact mark, core samples in a representative number of locations to check insulation condition, an infrared moisture scan of the full roof area, and a separate inspection of all rooftop equipment including HVAC units, exhaust vents, skylights, drains, and flashing details.

The inspector should also review the roof’s drainage design, since ponding water combined with hail-weakened seams is one of the most common causes of post-storm leaks. Any pre-existing wear, such as UV-degraded seams or previous patch repairs, should be documented separately from new hail damage so the insurance claim accurately reflects storm-caused loss versus pre-existing condition.

A written report following the inspection should include annotated photos, a summary of core sample findings, an infrared moisture map if applicable, and a clear recommendation distinguishing between areas needing spot repair and areas where damage severity justifies broader replacement. This level of documentation not only supports the insurance claim but gives the building owner a clear roadmap for budgeting the repair.

Serving Commercial Properties Across the GTA

Commercial hailstorm damage does not respect municipal boundaries, and our crews respond to calls across the entire Greater Toronto Area. We regularly inspect and repair commercial roofs in Toronto, throughout Peel Region including Mississauga and Brampton, across York Region communities like Markham and Vaughan, in Halton Region including Oakville and Burlington, and throughout Durham Region.

Because hailstorms tend to affect wide geographic bands rather than a single property, we frequently field multiple calls from the same business park or plaza after a single weather event. If your building is part of a shared roof system or a multi-tenant commercial plaza, coordinating inspection scheduling with neighbouring units can also help streamline any shared drainage or parapet repairs that affect more than one unit.

Need Help With 4 Essential Tips for?

Getting commercial roof hail damage repair right the first time protects your building, your tenants, and your insurance claim from unnecessary complications. Whatever stage your roof is at, from a suspected storm strike to a full replacement decision, Universal Roofs has the commercial roofing expertise to guide you through it.

Call us today at (416) 732-2421 or request a free inspection to get started.

Universal Roofs proudly serves Toronto, Mississauga, Brampton, Vaughan, Markham, Oakville and the GTA since 2005.