Key Concepts

Asphalt Shingles

• ASTM D3462: Standard for asphalt shingles made from glass felt — the primary quality standard for fiberglass-based shingles.
• ASTM D3018: Standard for asphalt shingles made from organic felt (Type I = mineral-surfaced, Type II = smooth-surfaced).
• Wind resistance tested per ASTM D7158; shingles must meet classification requirements per IBC Table 1504.2 for the applicable wind speed. Packaging must bear a label indicating the classification.

Underlayment (Steep-Slope)

• Asphalt felt: No. 15 or No. 30 felt; organic or fiberglass-reinforced. Traditional baseline underlayment.
• Synthetic underlayment: Polypropylene or polyester-based; lighter, stronger, and more tear-resistant than felt.
• Polymer-modified bitumen: SBS or APP modified; used where superior waterproofing or self-adhering capability is needed (common in eave protection/ice dam zones).

Roof Deck Substrates

• NRCA recommends direct attachment of asphalt shingles only to structural wood panel decks, wood plank, or wood board decks.
• Plywood: Structural rated panels; must meet APA/PS 1 standards.
• OSB (Oriented Strand Board): Must meet APA/PS 2; widely used, but more moisture-sensitive than plywood — requires proper ventilation.
• Wood planks: Minimum thickness and spacing requirements apply; spaced decking is used for wood shakes.
• NRCA does not recommend direct attachment to gypsum, concrete planks, cementitious wood fiber, or similar non-wood materials.
• Per IBC 1503.1, roof decks must be covered with approved coverings secured per the chapter's provisions.

Clay and Concrete Tile

• ASTM C1167: Standard specification for clay roof tiles.
• ASTM C1492: Standard specification for concrete roof tiles.
• Tiles are available as flat, low-profile (mission/barrel), and high-profile. Heavier than asphalt — structural loading must be confirmed.

Key Concepts

Asphalt Shingles

• Composed of asphalt, fillers, a reinforcing mat, and granule surfacing
• Strip shingles: typically 36" long; single-unit shingles: historically 12"×16"
• Impact-resistant (IR) shingles are Class 4 rated — important in hail-prone areas like Louisiana
• Minimum slope for standard application: 2:12 (with double underlayment); standard application at 4:12 and steeper
• Starter course required at eaves and rakes before field shingles

Underlayment

• Slope-based requirements are critical:
• 4:12 and steeper: Single layer #15 or #30 felt, or code-approved synthetic
• 2:12 to less than 4:12: Two layers minimum (low-slope modified application)
• Ice barrier (self-adhering): Required where average January temp ≤25°F — Louisiana generally exempt, but verify AHJ requirements

• 15 felt = older standard; #30 felt or synthetic underlayments provide greater tear resistance

• Self-adhering modified bitumen membranes used as high-performance underlayment or ice/water shield

Roof Deck Requirements

• Approved substrates: APA-rated plywood or OSB — minimum thickness based on rafter/truss spacing
• Boards must be well-seasoned, dry, and structurally sound
• Decks must be clean, dry, and free of voids before covering installation
• IBC 1503.1: Roof decks shall be covered with approved roof coverings secured per this chapter and manufacturer's instructions

Clay and Concrete Tile

• Clay tile: Naturally durable, heavier; requires structural analysis for load
• Concrete tile: More economical, similar weight concerns
• Fastening: Minimum 2 nails per tile for most applications; hip and ridge tiles require nailing or mortar
• Battens may be required for some profiles; underlayment beneath tile is critical (typically 2 layers #40 or equivalent)
• Minimum slope: generally 2½:12 for low-profile tile; 4:12 for high-profile tile

Key Concepts

Primary Roof Drainage (IBC §1502.1) Design and installation must comply with IBC §1502, §1611, and IPC Chapter 11. Roof decks must drain positively — ponding water is a structural and waterproofing failure risk.

Secondary (Emergency Overflow) Drains and Scuppers (IBC §1502.2–1502.3) - Required wherever roof perimeter construction (parapet walls, curbs) can trap water if primary drains fail or clog. - Scuppers must have a minimum opening dimension of 4 inches (102 mm) — this is a direct exam target. - Scupper quantity, size, location, and inlet elevation must prevent ponding depth from exceeding the roof's structural design limit (per §1611.1). - Do not count primary drain flow when sizing scuppers — size them as if the primary system does not exist.

Gutters (IBC §1502.4) - Gutters on buildings other than Group R-3, private garages, and Type V construction must be noncombustible material or Schedule 40 plastic pipe minimum. - Residential (R-3) and Type V buildings have more flexibility — but always verify material compatibility with roof covering type. - Flashing at gutters is required per §1503.2.1.

Flashing Requirements (IBC §1503.2) - Required at wall/roof intersections, gutters, changes in slope or direction, and around all roof openings. - Metal flashing minimum thickness: 0.019 inch (0.483 mm) — No. 26 galvanized sheet.

Crickets and Saddles (IBC §1503.5) - A cricket or saddle is required on the ridge side of any chimney or penetration greater than 30 inches (762 mm) wide, measured perpendicular to the slope. - Materials: sheet metal or same material as the roof covering. - Exception: Unit skylights flashed per manufacturer's instructions do not require a cricket.

(7 questions, 14% of exam)

Key Concepts

Roof Slope Measurement - Rise = vertical height; Run = horizontal distance (half the span); Span = full width of building - Pitch = Rise ÷ Span (fraction); Slope = Rise ÷ Run (expressed as X-in-12) - Example: 4-in-12 slope = 4" rise per 12" run; pitch = 4/24 = 1/6 - Steep-slope roofing generally applies at 4:12 and above; low-slope below 4:12

Roof Deck Types: Solid vs. Spaced Sheathing - Solid sheathing (plywood/OSB): Required for asphalt shingles, modified bitumen, metal panels, and most residential coverings - Spaced sheathing (1×4 or 1×6 boards with gaps): Acceptable for wood shakes and wood shingles only, allowing airflow underneath - Matching deck type to covering type is a code requirement — using spaced sheathing under asphalt shingles is a defect

Plywood and OSB Sheathing Specifications - Panels must carry an APA span rating — the rating appears as two numbers (e.g., 24/16 = 24" roof span / 16" floor span) - Minimum thickness for 24" rafter spacing: 7/16" OSB or 3/8" plywood (verify APA span rating) - Panels should be installed with the long dimension perpendicular to rafters, staggered joints, with 1/8" gap at edges and ends for expansion - Edge support (blocking or H-clips) required when span exceeds panel rating

Dead Loads vs. Live Loads - Dead load: Weight of permanent materials — shingles (~2–3 psf), tile (~9–12 psf), deck, framing - Live load: Temporary loads — occupancy, snow, construction workers/equipment (typically 20 psf minimum for residential roofs per IBC) - Heavier materials (tile, slate) require structural verification before re-roofing over existing lightweight covering

(5 Questions, 10% of Exam)

Key Concepts

Fall Protection Triggers (29 CFR 1926.502) - Low-slope roofs (≤4:12 pitch): Use guardrail systems, safety net systems, or personal fall arrest systems (PFAS). Alternatively, use a warning line system combined with a safety monitoring system or a warning line combined with PFAS. - Steep roofs (>4:12 pitch): Guardrail systems with toeboards, safety net systems, or PFAS are required. Warning line systems alone are not permitted on steep roofs. - Fall protection is required at 6 feet above a lower level for residential/construction roofing work.

Personal Fall Arrest System (PFAS) Components & Specs - Components: Full-body harness, lanyard, deceleration device, anchor point, and connecting hardware. - Anchor must support 5,000 lbs. per employee attached. - System must limit free fall to 6 feet and bring worker to a stop with no more than 1,800 lbs. of arresting force. - Must not allow worker to contact a lower level. - After a fall arrest, the system must be removed from service and inspected before reuse. - Inspect before each use for mildew, wear, damage, and deterioration.

Guardrail System Specifications - Top rail height: 42 inches (±3 inches) above walking/working surface. - Midrail: Midway between top rail and walking surface (approximately 21 inches). - Top rail must withstand 200 lbs. of force in any outward or downward direction. - Midrail must withstand 150 lbs. - Toeboards: Minimum 3.5 inches tall; openings no greater than 1 inch.