IL Roofing Contractor cheat sheet

The Illinois Roofing Industry Licensing Act (225 ILCS 335) establishes state roofing contractor licensure; IDFPR administers licensing, examinations, and discipline.

A state roofing contractor license requires proof of general liability insurance and workers' compensation coverage or an approved exemption.

Illinois Home Repair and Remodeling Act: a written contract and consumer-rights brochure are required for home repair contracts over $1,000.

Local permits and licenses are separate: Chicago and many municipalities require their own roofing contractor license and permit before work begins.

Illinois employers must carry workers' compensation; independent contractors must meet common-law and statutory tests to avoid employee status.

Unlicensed contracting can lead to cease-and-desist orders, fines, and loss of lien rights; licenses are not transferable.

The Mechanics Lien Act permits unpaid contractors and suppliers to claim a lien, but owner-occupied residential projects have notice prerequisites.

Contractors must provide lien waivers and sworn statements when requested; final payment should be tied to written acceptance.

Roof area = horizontal footprint area × slope factor; slope factor = √(1 + (rise ÷ run)²) with run expressed in the same units.

Pitch multipliers: 4/12=1.054, 5/12=1.083, 6/12=1.118, 7/12=1.158, 8/12=1.202, 9/12=1.250, 10/12=1.302, 12/12=1.414.

Roofing squares = roof area ÷ 100; most 3-tab shingles ship 3 bundles per square, and many architectural shingles also ship 3 bundles per square at heavier weight.

Waste allowance: 10% for simple gable roofs, 15% for hips and valleys, and 20% for complex roofs with multiple penetrations and direction changes.

Net free ventilation area: 1 sq ft per 150 sq ft of attic floor area, or 1 per 300 sq ft when a vapor barrier is installed.

Ice-and-water membrane at eaves extends 24 inches inside the exterior wall line and is installed over the underlayment at the eave.

Contract documents control: specifications govern materials and methods, drawings govern dimensions; request written clarification for conflicts.

Bid quantity takeoff includes decking, underlayment, ice barrier, shingles, ridge/hip cap, starter, flashing, vents, fasteners, and dumpster.

Asphalt shingles consist of a fiberglass mat saturated and coated with asphalt and surfaced with mineral granules; the fiberglass mat resists tearing and moisture.

3-tab shingles are single-layer and lighter; laminated architectural shingles use multiple layers for thicker profile and higher wind ratings.

Underlayment options include asphalt-saturated felt (15 lb or 30 lb) and synthetic polymer sheets; synthetic is lighter and tear-resistant.

Ice-and-water shield is a self-adhering rubberized asphalt membrane used at eaves, valleys, and penetrations to resist ice dams.

Metal flashing types: drip edge at eaves and rakes, step flashing at sidewalls, apron flashing at headwalls, and valley flashing in valleys.

Low-slope membranes: TPO (heat-welded thermoplastic), EPDM (adhesive-seamed rubber), modified bitumen (torch or cold-applied), and built-up roofing.

Ridge and hip cap shingles cover cut edges; starter strip along eaves and rakes improves wind resistance and seals shingle tabs.

Roof ventilation pairs intake at soffits with exhaust at ridge or static vents; balanced airflow prevents condensation and heat buildup.

Asphalt shingles require a minimum 2/12 slope; from 2/12 to 4/12, double underlayment is required; below 2/12, use a low-slope membrane system.

Fasten shingles through the nail line with 4 nails per shingle for standard 3-tab and 6 nails for high-wind or architectural applications.

Nails must penetrate roof sheathing at least 3/4 inch or pass through the deck; high nails and overdriven nails reduce wind resistance.

Open valleys use metal valley flashing under shingles; closed valleys weave or cut shingles over a valley underlayment.

Low-slope roofs must drain at 1/4 inch per foot minimum; ponding indicates inadequate slope, deflection, or clogged drains.

TPO seams are cleaned and heat-welded; EPDM seams use contact adhesive or seam tape; modified bitumen is torch-applied or cold-adhered.

Underlayment laps: asphalt-saturated felt side laps 2 inches and end laps 4 inches, with upper courses lapping over lower courses down-slope.

Install ice-and-water membrane at eaves, valleys, and around penetrations before underlayment; do not fasten through membrane except as required.

OSHA requires fall protection for construction workers exposed to 6 feet or more; roofing work on low-slope roofs also triggers warning-line or guardrail rules.

Personal fall arrest systems use a full-body harness, lanyard, connector, and anchorage rated at 5,000 pounds per worker.

Extension ladders must extend 3 feet above the landing, be set at a 4:1 angle, and be secured at the top or bottom.

Guardrails must be 42 inches high (±3 inches) with a midrail at 21 inches and toe boards where falling objects are a hazard.

IRC requires ice barrier underlayment at eaves where average January temperature is 25°F or lower, extending 24 inches inside the wall line.

Attic ventilation code: 1/150 net free area, or 1/300 when balanced intake and exhaust and a vapor barrier are provided.

Roof coverings must meet fire classification and wind-resistance requirements; asphalt shingles are typically Class A and rated by ASTM D3462.

Jobsite housekeeping: keep cords, tools, and debris off walking surfaces; use GFCI protection for temporary power.