- Exam Overview: How CTS Structures the Roofer Exam
- Domain 1: Safety & Employee Protection
- Domain 2: Roofing Preparation & Materials
- Domain 3: Steep-Slope Roofing Systems
- Domain 4: Low-Slope Roofing Systems
- Domain 5: Rules, Regulations & Business Practices
- Domain 6: Non-Residential Roofing Systems
- Domain Weighting at a Glance
- Mapping a Study Schedule to the Domains
- FAQ
- Steep-Slope Roofing Systems is the largest domain at 35 of 130 questions - study it first and longest.
- Safety & Employee Protection is second-heaviest at 25 questions, testing OSHA-aligned jobsite practices.
- Rules, Regulations & Business Practices (20 questions) covers Illinois law, bonding, and insurance limits.
- All six domains total 130 multiple-choice items in 150 minutes; 70% correct is the passing threshold.
Exam Overview: How CTS Structures the Roofer Exam
The Illinois Residential, Commercial and Industrial Roofing Examination - the credential most people mean when they say IL-ROOF - is administered by Continental Testing Services (CTS) on behalf of the Illinois Department of Financial and Professional Regulation. It's the direct route to the unlimited roofing license (profession 105, test 03). This is not a generic trade quiz; it's a fixed 130-question, multiple-choice exam delivered in 150 minutes, with a passing score of 70 or higher. Every question on that exam falls into one of six official content domains, and CTS publishes exact item counts for each.
Understanding those six domains - and exactly how many questions each one carries - is the single most efficient way to plan your prep. If you haven't already reviewed the mechanics of registration and fees, our IL-ROOF Requirements breakdown and IL-ROOF Certification Cost guide cover the $248 CTS exam fee and the separate $125 IDFPR business-license application. This article focuses purely on content: what's tested, how much, and what you need to know inside each area.
Domain 1: Safety & Employee Protection (25 Questions)
Safety & Employee Protection is the second-largest domain on the exam, and for good reason: roofing is one of the higher-risk construction trades, and Illinois wants qualifying parties who can run a jobsite without exposing crews to preventable hazards. Expect questions on fall protection systems, ladder and scaffold safety, personal protective equipment, hazard communication, and the general safety expectations that apply to residential, commercial, and industrial roofing crews alike.
Domain 1: Safety & Employee Protection
Candidates must understand how to identify and mitigate common roofing hazards and communicate safety expectations to a crew.
- Fall-protection anchor points, guardrails, and personal fall-arrest systems
- Ladder setup, scaffold access, and material-handling hazards
- PPE requirements specific to steep-slope and low-slope work
- Employer responsibilities for training and supervision on active roofs
Because this domain carries 25 of 130 questions, treat it as a near-must-pass section on its own. Weak safety knowledge can sink an otherwise strong score, especially since safety concepts also bleed into the steep-slope and non-residential domains later in the exam.
Domain 2: Roofing Preparation & Materials (20 Questions)
This domain covers what happens before shingles or membrane ever go down: substrate inspection, deck preparation, underlayment selection, fastener types, and material compatibility. Questions here often test whether a candidate knows which materials pair correctly with which roof types and climate conditions common in Illinois.
Domain 2: Roofing Preparation & Materials
Candidates must know how to evaluate and prepare a roof deck and select appropriate materials before installation begins.
- Deck inspection and repair prior to roofing installation
- Underlayment types and correct application methods
- Fastener selection and spacing for different substrates
- Material storage, handling, and manufacturer specification compliance
The current CTS-linked study guide (dated May 2021) points candidates toward NRCA roofing references for exactly this kind of material-level detail, alongside waterproofing and repair guidance that overlaps with both the steep-slope and low-slope domains.
Domain 3: Steep-Slope Roofing Systems (35 Questions)
Steep-Slope Roofing Systems is, by a wide margin, the largest domain on the exam - 35 of 130 questions, more than a quarter of the entire test. If you only had time to master one domain, this would be it.
Domain 3: Steep-Slope Roofing Systems
Candidates must demonstrate detailed knowledge of installing, flashing, and troubleshooting pitched-roof systems.
- Shingle, shake, tile, slate, and metal panel installation sequencing
- Flashing details at valleys, chimneys, sidewalls, and penetrations
- Ventilation and ice-and-water-shield practices for Illinois climate exposure
- Common failure points and repair techniques on steep-slope assemblies
Given its weight, this domain deserves the longest block of your study calendar. Our IL-ROOF Study Guide 2026 walks through a domain-by-domain review order that puts steep-slope prep front and center.
Domain 4: Low-Slope Roofing Systems (15 Questions)
Low-Slope Roofing Systems covers the membrane-based, near-flat roof assemblies common on additions, porches, and smaller commercial applications: built-up roofing, modified bitumen, single-ply membranes, and related drainage and waterproofing considerations. At 15 questions, it's tied for the smallest domain, but the material still shows up on real Illinois jobsites and can't be skipped.
Domain 4: Low-Slope Roofing Systems
Candidates must understand membrane roofing installation, seaming, and drainage principles.
- Built-up, modified bitumen, and single-ply membrane installation basics
- Seam sealing and membrane fastening approaches
- Slope, drainage, and ponding-water prevention
- Flashing and transition details between low-slope and steep-slope sections
Domain 5: Rules, Regulations & Business Practices (20 Questions)
This domain is where the exam shifts from field craft to office and legal responsibility. It draws directly from the NASCLA business material and Illinois law and rules referenced in the CTS study guide, plus the licensing regulations under 68 Ill. Admin. Code 1460.
Domain 5: Rules, Regulations & Business Practices
Candidates must know the legal and financial obligations tied to holding an Illinois roofing license.
- Licensing categories: unlimited license vs. the commercial/industrial-only upgrade requiring prior residential qualification
- The $25,000 continuous surety bond requirement (bond face amount, not premium)
- Minimum coverage: at least $250,000 property-damage and $500,000 personal-injury/bodily-harm per occurrence, plus applicable employment coverage
- License expiration on December 31 of odd-numbered years (next: December 31, 2027) and renewal at $62.50 per year or $125 for the standard two-year cycle
- Basic contract, estimating, and lien-related business obligations
Because these are hard legal figures rather than judgment calls, this domain rewards straightforward memorization more than any other. Our IL-ROOF Cheat Sheet 2026 condenses these bonding and renewal numbers into a single quick-reference page, and IL-ROOF Passing Score 2026 explains exactly how the 70% threshold applies across all six domains combined.
Key Takeaway
Domain 5 numbers ($25,000 bond, $250,000/$500,000 coverage minimums, biennial renewal fees) are fixed facts you either know cold or guess on - memorize them explicitly rather than trying to "reason" your way to the answer.
Domain 6: Non-Residential Roofing Systems (15 Questions)
Non-Residential Roofing Systems rounds out the exam with 15 questions focused on larger-scale commercial and industrial roofing scenarios: bigger membrane systems, insulation and fire-rating considerations, and the coordination challenges that come with non-residential structures. This domain overlaps conceptually with Domain 4 but applies those principles at commercial and industrial scale.
Domain 6: Non-Residential Roofing Systems
Candidates must apply roofing principles to commercial and industrial-scale buildings.
- Insulation layering and fire/wind-rating considerations for larger structures
- Rooftop equipment penetrations, curbs, and expansion joints
- Coordination between roofing crews and other building trades on larger projects
- Differences between the unlimited license scope and the commercial/industrial-only upgrade path
Since the commercial/industrial-only upgrade path requires prior residential qualification, this domain matters most to candidates already working toward, or holding, a broader scope of licensure.
Domain Weighting at a Glance
Here's the full official CTS item allocation across all six domains, in order:
| Domain | Questions | Share of Exam |
|---|---|---|
| 1. Safety & Employee Protection | 25 | ~19% |
| 2. Roofing Preparation & Materials | 20 | ~15% |
| 3. Steep-Slope Roofing Systems | 35 | ~27% |
| 4. Low-Slope Roofing Systems | 15 | ~12% |
| 5. Rules, Regulations & Business Practices | 20 | ~15% |
| 6. Non-Residential Roofing Systems | 15 | ~12% |
| Total | 130 | 100% |
For a deeper look at how this compares to what candidates actually experience test-day, see How Hard Is the IL-ROOF Exam? and IL-ROOF Pass Rate 2026.
Mapping a Study Schedule to the Domains
Rather than studying domains in numerical order, allocate time proportional to question weight. Steep-Slope Roofing Systems (35 questions) and Safety & Employee Protection (25 questions) together make up nearly half the exam, so they deserve nearly half your study hours.
Steep-Slope Roofing Systems
- Review shingle, tile, slate, and metal panel installation sequencing
- Drill flashing details at valleys, chimneys, and penetrations
Safety & Employee Protection + Roofing Preparation & Materials
- Study fall-protection and PPE requirements
- Review deck prep, underlayment, and fastener selection
Rules, Regulations & Business Practices + Low-Slope Systems
- Memorize bonding, insurance, and renewal figures
- Cover membrane roofing installation and drainage basics
Non-Residential Systems + Full Review
- Study commercial/industrial-scale roofing considerations
- Take timed practice sets covering all six domains proportionally
This weighting-first approach is covered in more depth in the IL-ROOF Study Guide 2026, which also details registration logistics like the October 7, 2026 deadline for the November 4, 2026 exam date at CTS's Hillside and Springfield locations - details worth reviewing alongside our IL-ROOF Exam Dates 2026 guide.
If you're still deciding whether this credential fits your career plans, Is the IL-ROOF Certification Worth It? and IL-ROOF Salary Guide 2026 look at the bigger-picture case, while IL-ROOF Jobs covers who actually hires licensed roofing contractors in Illinois. You can also start reviewing domain-weighted practice questions right now on the main practice test platform.
Frequently Asked Questions
Steep-Slope Roofing Systems is the largest domain with 35 of 130 questions, followed by Safety & Employee Protection with 25.
There are six official content domains: Safety & Employee Protection, Roofing Preparation & Materials, Steep-Slope Roofing Systems, Low-Slope Roofing Systems, Rules, Regulations & Business Practices, and Non-Residential Roofing Systems.
Yes. Rules, Regulations & Business Practices accounts for 20 of 130 questions and covers Illinois law, bonding, and insurance minimums drawn from NASCLA business material and Illinois statutes.
No. Low-Slope Roofing Systems and Non-Residential Roofing Systems each carry 15 questions - together nearly a quarter of the exam - so skipping either risks the 70% passing threshold.
The six-domain structure and exact item counts (25, 20, 35, 15, 20, 15) come from Continental Testing Services' official allocation for the Illinois Residential, Commercial and Industrial Roofing Examination.