Authored by: Rimkus Built Environment Solutions Marketing Team
Calgary’s August 5, 2024, hailstorm caused an estimated $3.349 billion in insured losses, according to Catastrophe Indices and Quantification Inc. (CatIQ), making it Canada’s largest hail catastrophe. For commercial, industrial, and multi-family owners in the region, that single storm illustrates a recurring exposure, not an isolated event.
Calgary sits within one of Canada’s most hail-prone regions, and recurring exposure makes building envelope condition, material selection, and capital planning ongoing considerations, not one-time concerns. Vulnerability that goes unaddressed between storms tends to compound, since roofing, cladding, glazing, and rooftop equipment weakened by one event typically carry less reserve for the next.
This guide looks at why Calgary experiences recurring hail exposure, how building condition shapes the extent of hailstorm building damage when a storm hits, and what routine assessment, material selection, and capital planning steps property owners can take between storms. It also covers how reserve fund studies help translate that exposure into a defensible long-term plan.
Key takeaways: Hailstorm building damage risk in Calgary
Hail Alley’s recurring exposure makes building condition, material choice, and capital planning central to limiting hailstorm building damage over time. The sections below summarize how owners can reduce vulnerability between storms.
Why building condition matters before a storm arrives
Existing weaknesses in roofing, cladding, or glazing tend to worsen with repeated hail exposure, and much of that damage stays hidden until a system fails outright.
- Southern and central Alberta experiences at least one major hailstorm most years
- Damage is frequently concealed within a roof assembly or wall system, so an intact-looking surface after one storm may already carry reduced resistance to the next
How owners build resilience over time
Routine assessment and planned material upgrades give owners a way to get ahead of storm damage instead of reacting to each event individually.
- Routine envelope assessment can identify vulnerability before it becomes storm damage
- Impact-resistant material specification and reserve fund planning reduce exposure across a capital planning cycle
Why Calgary is prone to hail damage
Southern and central Alberta is recognized as one of Canada’s most hail-prone regions, a corridor often called Hail Alley that runs from High River through Calgary, Red Deer, and Lacombe.
The Rocky Mountain foothills push air upslope and promote storm development west and northwest of the city, and because the ground sits at higher elevation, hail may fall a shorter distance through warmer air, letting more large stones reach the ground intact.
Alberta has experienced at least one major hailstorm every year for the past two decades. The July 13, 2025 Calgary hailstorm was another example, ultimately causing an estimated $164 million in insured damage. Repeated events are what make hail exposure an ongoing planning consideration rather than a one-time recovery issue.
This frequency, more than any single storm, is what makes hail exposure an ongoing planning consideration for commercial and multi-family owners in the region, not a risk that resolves once one claim closes. Portfolios spanning multiple Calgary properties are effectively planning around the near-certainty of another significant event within a typical capital planning horizon, not a remote possibility.
Building condition affects how much damage a storm causes
Hail affects roofing and membrane systems, exterior cladding, glazing, and rooftop mechanical equipment in different ways, and the condition of each system going into a storm shapes how much damage results. A building envelope assessment that only reviews the roof can miss vulnerability building in the other three systems.
Roof membranes can lose performance well before any damage is visible from a walkable surface; at one airport terminal, cracks attributed to hail began on the underside of the membrane with no sign visible from the top. A commercial roof inspection that checks only what a technician can see from a walkable path can miss deterioration of this kind between storms.
Cladding and siding materials vary substantially in how they tolerate impact, and product-specific information is generally a more reliable guide to a given assembly’s resilience than assuming one material class behaves like another. Some cladding systems show cracking in an outer coating well before surface evidence is visible from ground level, and certain metal wall panels can carry dents small enough to escape a routine visual check entirely.
Glazing that has already been scratched or has a seal beginning to weaken carries less structural reserve for the next impact, and fogging between panes is a typical early sign that a seal has failed.
Rooftop HVAC equipment with flattened cooling fins from a prior event may already be operating at reduced capacity, independent of any damage a future storm adds. Because these four systems are typically assessed separately by different trades, a coordinated review across roofing, cladding, glazing, and mechanical equipment tends to surface vulnerability that a system-by-system check misses.
Routine assessment can identify vulnerability before a storm finds it
A roof surface that still looks intact can conceal cracked reinforcing layers or insulation that has absorbed moisture and lost a meaningful share of its insulating value. Storm damage evaluation methods used after a loss are the same methods that can establish a condition baseline beforehand, as part of routine envelope maintenance.
- Infrared thermography can identify thermal anomalies consistent with wet insulation, with suspected areas confirmed through core samples or moisture probes
- Moisture-detection methods such as capacitance, impedance, or nuclear scanning can indicate suspect areas, though each has material-specific limitations
- Periodic core sampling can verify assembly composition and moisture content as part of a scheduled maintenance program, not only after a loss event
Establishing this kind of baseline periodically, not only after a storm, gives an owner a documented reference point for what changed and how quickly. Dated pre-loss condition assessments also help distinguish storm-related change from an installation defect or ordinary wear whenever a claim eventually arises, since policies generally do not cover pre-existing conditions.
Impact-resistant material selection is a practical resilience lever
Roofing products carrying a documented impact-resistance rating appropriate to the assembly, such as UL 2218 Class 4 asphalt shingles, are one of the more direct ways an owner can reduce future hail vulnerability at the point of replacement or major repair.
Testing standards, warranty terms, code compliance, and insurer eligibility vary by product, so confirming these for the specific assembly under consideration is a useful step before specifying a replacement material.
Because cladding and glazing tolerance also varies by product rather than by general material category, the same logic applies across the envelope. An owner planning a re-roof, recladding, or window replacement in Hail Alley has an opportunity to factor documented impact resistance into that decision, instead of treating storm resilience as a separate, later consideration.
Reserve fund studies build hail resilience into long-term capital planning
Reserve fund studies give condo boards a documented basis for planning major repairs and replacements around Hail Alley’s recurring exposure, and Alberta’s Condominium Property Regulation requires one at least once every five years, typically covering a planning horizon of 30 years or more.
Dated property condition assessments and routine inspections feed directly into that study, establishing what a building looked like at a given point and creating useful context for both maintenance planning and any future claim. A reserve fund study built on reliable, current condition records gives a board a defensible basis for planning envelope replacement and repair timing, instead of treating each storm as an unplanned expense. Condominium consulting services can help align routine condition assessment with that longer planning cycle.
Building resilience into a recurring risk
Calgary’s position in Hail Alley makes recurring storm exposure a standing planning consideration for commercial and multi-family portfolios, not a one-time event to recover from. Building condition, material specification, and capital planning are the levers available to an owner between storms, and each works better when informed by current, documented assessment rather than assumption.
When damage does occur, a forensic damage assessment connects physical evidence across the roof, envelope, and mechanical systems to support a cause-and-origin determination and a defined repair scope. Building that resilience beforehand, though, is what determines how much of that work is ever needed.
Interested in learning more about Calgary hailstorm building damage? Get in touch.
Frequently asked questions about Calgary hailstorm building damage
Which roofing products may reduce future hail damage?
Products with a documented impact-resistance rating appropriate to the assembly, such as UL 2218 Class 4 asphalt shingles, can help reduce future hail damage. Confirming testing, warranty, and code details for the specific assembly is worthwhile before specifying a replacement.
How often should a commercial building envelope be assessed in a hail-prone region?
There is no single fixed interval. Assessment frequency should reflect roof and envelope age, material type, previous findings, maintenance history, and recent storm exposure, with additional assessment after significant events when warranted.
How does a reserve fund study account for recurring hail exposure?
A reserve fund study projects the timing and cost of major repairs and replacements over a multi-year horizon, informed by current envelope condition data. Boards in hail-prone regions use these studies to plan envelope replacement proactively, rather than only after a damaging storm.
This article is intended to provide general information and insights into prevailing industry practices. It is not intended to constitute, and should not be relied upon as, legal, technical, or professional advice. The content does not replace consultation with a qualified expert or professional regarding the specific facts and circumstances of any particular matter.