Commercial Roofing in Chicago: What Building Owners Should Know

Commercial roofing in Chicago presents challenges that building owners in milder climates simply do not face. The combination of extreme winter cold, summer heat, high winds, heavy snow loads, and frequent freeze-thaw cycling puts extraordinary stress on roofing systems. Add in the city's rigorous building codes and permitting requirements, and it becomes clear why choosing the right roofing contractor and system in Chicago requires more thought than in most other markets.

Windward Roofing & Construction has been headquartered in Chicago since 1984. We have worked through every type of weather the city can produce, navigated its building department processes on hundreds of projects, and developed a deep understanding of what it takes for a commercial roof to perform reliably in this environment. This guide shares that knowledge to help Chicago building owners make informed decisions about their most important building component.

Chicago's Climate: What Your Roof Is Up Against

Chicago's climate is defined by extremes. Winter temperatures regularly drop below zero, summer temperatures climb into the 90s, and the transition seasons bring rapid swings that subject roofing materials to constant thermal stress. Understanding these conditions is the first step toward choosing a system that will perform reliably.

Winter conditions. Chicago averages over 35 inches of snowfall per year, with individual storms occasionally delivering a foot or more in a single event. Temperatures can remain below freezing for weeks at a time, creating sustained stress on roofing membranes and flashings. Freeze-thaw cycles are particularly damaging because water that enters small cracks or openings during a daytime thaw expands when it refreezes at night, widening the damage with each cycle.

Snow loads. The ground snow load for Chicago is 25 pounds per square foot, and actual roof loads can exceed this in areas where snow drifts against parapets, equipment curbs, or taller adjacent structures. Large flat roofs on warehouses, manufacturing plants, and retail buildings are especially vulnerable because their wide spans amplify the consequences of snow overloading.

Wind exposure. Chicago's reputation as the Windy City is well-earned from a roofing perspective. The city sits on the flat shore of Lake Michigan, exposing buildings to sustained winds and powerful gusts, particularly during spring and fall storms. High-rise buildings and those in open or lakefront locations experience even greater wind pressures. Wind is a primary cause of commercial roof damage in the Chicago area, making proper wind uplift design and installation critical.

Summer heat. While winter gets most of the attention, Chicago summers create their own roofing challenges. Roof surface temperatures can exceed 150 degrees on dark-colored membranes, accelerating aging and increasing cooling costs for the building below. The temperature differential between a hot summer afternoon and a cool summer night subjects the roofing assembly to daily thermal cycling that fatigues materials over time.

Hail. The Chicago metropolitan area experiences damaging hail events several times per decade. Hailstones can puncture single-ply membranes, crack modified bitumen, and dent metal roofing. After any confirmed hail event, a professional roof inspection should be conducted promptly to identify and document any damage before it leads to leaks.

Best Commercial Roofing Systems for Chicago

Every major commercial roofing system can work in Chicago when properly designed and installed. However, some systems are better suited to the city's specific demands than others. Here are the most commonly installed systems on Chicago commercial buildings and how each performs in this climate.

TPO roofing is the most widely installed commercial membrane in the Chicago area. Its white reflective surface provides meaningful energy savings during hot summers, while modern formulations handle cold-weather installation and winter performance well. Heat-welded seams provide superior resistance to wind uplift and water intrusion. TPO is an excellent all-around choice for Chicago buildings of all types.

EPDM roofing remains extremely popular in Chicago and throughout the Midwest because of its proven cold-weather performance. EPDM stays flexible at temperatures well below zero, making it naturally resistant to the cracking and splitting that can affect stiffer materials during extreme cold. Its lower upfront cost also makes it attractive for large buildings where material savings add up significantly. The trade-off is that standard black EPDM increases cooling costs during summer.

Modified bitumen is a strong performer in Chicago because SBS-modified products maintain flexibility in extreme cold while providing the multi-ply redundancy that protects against leaks. Modified bitumen is especially well-suited for roofs with heavy foot traffic or rooftop equipment, as its granule surface resists physical damage better than single-ply membranes.

Built-up roofing (BUR) has a long and successful history on Chicago commercial buildings. Its multi-layer construction provides exceptional durability and fire resistance. The gravel surfacing protects against hail and UV damage. BUR is particularly common on older Chicago buildings and remains a reliable choice for new construction and re-roofing projects where its weight is not a concern.

Metal roofing is growing in popularity on Chicago commercial buildings, particularly on newer construction and pre-engineered metal buildings. Standing seam metal provides excellent wind resistance, long lifespan, and low maintenance. However, metal roofs require adequate slope and careful detailing to handle Chicago's snow loads and freeze-thaw conditions.

Chicago Building Code and Wind Uplift Requirements

Chicago's building code is among the most stringent in the country, and commercial roofing projects must comply with detailed requirements that affect system design, material selection, and installation methods.

Wind uplift design. All commercial roofs in Chicago must be designed to resist wind uplift forces calculated based on the building's height, exposure category, and importance factor. The code requires higher wind resistance at roof perimeters and corners, where negative pressure during wind events is greatest. This affects fastener spacing, adhesive application rates, and membrane thickness specifications. Roofing systems must be tested and rated to meet the calculated uplift pressures, and the manufacturer's installation specifications must be followed exactly to validate the warranty and meet code requirements.

Energy code compliance. The current Illinois Energy Conservation Code requires minimum insulation values for commercial roofs. For new construction and major re-roofing projects, the roof assembly must meet or exceed the prescribed R-value, which typically requires 25 to 30 R-value or more depending on the building type and climate zone. This affects the type and thickness of insulation installed beneath the roofing membrane.

Fire ratings. Chicago requires commercial roofs to meet specific fire classification standards. Most common commercial roofing systems achieve Class A fire ratings (the highest level), but the specific assembly, including insulation type, cover board, and membrane, must be tested and approved as a complete system.

Permits and the Approval Process

Commercial roof replacement in Chicago requires a building permit from the Department of Buildings. The permit process involves several steps that building owners should understand and plan for.

Application submission. The roofing contractor submits a permit application along with project plans, specifications, and documentation showing code compliance. For straightforward re-roofing projects, this is typically a standard permit application. Larger or more complex projects may require full architectural plans and structural engineering review.

Review timeline. Standard permit review in Chicago takes 2 to 6 weeks, depending on the project complexity and the department's current workload. Expedited review may be available for an additional fee. Planning ahead is essential because delays in permitting translate directly into delays in getting your roof installed.

Inspections. The city conducts inspections during and after the roofing installation to verify compliance with the approved plans and applicable codes. Your contractor is responsible for scheduling these inspections and ensuring the work is ready for review.

Contractor responsibility. A qualified commercial roofing contractor should handle the entire permit process on your behalf, including application preparation, plan submission, code research, and inspection coordination. If a contractor asks you to pull the permit yourself, consider it a warning sign about their experience and professionalism.

Seasonal Timing for Commercial Roofing Projects

While experienced contractors can install commercial roofing systems year-round in Chicago, understanding the seasonal considerations helps you plan your project for the best outcome.

Late April through October is the prime roofing season in Chicago. Temperatures are consistently warm enough for optimal adhesive curing, membrane handling, and coating application. Longer daylight hours also allow more productive work days. If your project is not urgent, scheduling within this window provides the most consistent working conditions.

November through March presents cold-weather challenges, but roofing work does not stop. TPO can be heat-welded in cold temperatures with experienced crews. EPDM's flexibility makes it easier to handle in winter than most other membranes. Modified bitumen can be torched or hot-mopped in cold weather with appropriate precautions. The primary materials that become difficult in winter are water-based adhesives and coatings, which require minimum application temperatures to cure properly.

Planning tips for Chicago building owners:

• Begin the contractor selection and proposal process 2 to 3 months before your desired start date
• Allow 2 to 6 weeks for the permit process
• Factor in weather contingency days, especially for spring and fall projects when rain is most frequent
• If you need a roof replaced before winter, start the process no later than mid-summer to ensure adequate time for contractor scheduling, permitting, and material procurement
• For emergency situations, do not wait for ideal weather. Contact an emergency roofing contractor immediately to make temporary repairs that protect the building until a permanent solution can be scheduled

What to Expect During a Commercial Roof Replacement

Understanding the typical process helps you plan for the disruption and communicate with tenants and building occupants.

Pre-construction. Your contractor will conduct a detailed site survey, finalize material selections, submit for permits, and coordinate material deliveries. This phase typically takes 3 to 6 weeks after contract signing.

Tear-off and preparation. The existing roofing system is removed down to the structural deck, which is then inspected for damage, rot, or deterioration. Any deck repairs are completed before new materials are installed. Tear-off generates significant noise and debris, which your contractor should manage with dumpsters, debris chutes, and daily cleanup.

Installation. New insulation, cover boards, and the roofing membrane are installed according to the manufacturer's specifications. Flashings, edge details, and penetration sealing are completed. The installation timeline depends on roof size, system type, and weather but typically ranges from one to four weeks for an average commercial building.

Final inspection and warranty. The city inspector verifies code compliance, and the roofing manufacturer conducts their own inspection (for projects that qualify for manufacturer warranties). Once both inspections are passed, the warranty documentation is issued and the project is complete.

Why Local Experience Matters

Commercial roofing in Chicago is not the same as commercial roofing in Dallas, Denver, or Atlanta. The climate demands, code requirements, permitting processes, and construction logistics are specific to this market. Working with a contractor who has deep roots in the Chicago area ensures that your project benefits from local expertise at every stage.

Windward Roofing & Construction has operated from our Chicago headquarters since 1984. We know the building department staff, understand the code requirements, have relationships with local material suppliers for fast procurement, and have the equipment and crews to work effectively in every season. Whether your building is in the Loop, the near suburbs, or the greater metropolitan area, we bring four decades of Chicago-specific experience to every project.

Contact us to discuss your commercial roofing needs. We provide free consultations, detailed proposals, and honest recommendations tailored to your building and budget.

Frequently Asked Questions