Louisiana Roofing, Sheet Metal and Siding

Key Concepts

Measuring Roof Area - Level (flat) roofs: Area = Length × Width of the horizontal footprint. No slope factor adjustment needed. - Sloped roofs: Multiply the level (plan view) area by the appropriate slope factor to get true surface area. Slope factors are tabulated in Appendix A of Roofing Construction & Estimating. - Net vs. Gross area: Gross area includes all surfaces; net area deducts openings (skylights, chimneys). Use net area for material takeoff. - Overhangs, hips, and valleys must be included in total roof area calculations — measure to the drip edge, not the wall line.

Slope and Pitch - Slope is expressed as rise over run (e.g., 4:12 = 4 inches of rise per 12 inches of horizontal run). - Pitch = Total Rise ÷ Total Span (span = 2× run). A 4:12 slope ≠ 4/12 pitch. - Slope factor converts plan area to actual roof surface area. A 4:12 slope has a slope factor of approximately 1.054; steeper slopes have higher factors.

Key Concepts

Roof Deck Inspection Requirements Before applying any roofing materials, the deck must be broom clean, reasonably smooth, free of voids or depressions, and adequately attached. The inspection should include the roofing contractor plus appropriate parties (GC, deck contractor, architect/engineer, owner's representative). If defects are found, corrections must be made and a second inspection must occur — attended by the same parties — before work begins.

Roofing contractor responsibility is limited: You can only inspect the surface. You cannot assume responsibility for slope, structural integrity, method of attachment, or below-deck conditions.

Acceptable Deck Substrates for Asphalt Shingles NRCA recommends direct attachment only to: - Structural wood panel decks (plywood or OSB) - Wood plank or wood board decks (must be continuous/closely spaced — spaced or "skipped" planks are not acceptable)

Non-wood materials (gypsum, concrete planks, cementitious wood fiber, metal) are not acceptable for direct attachment. If these are encountered, install a nailable wood substrate over them first.

Plywood Specifications (PS 1 Standard) - NRCA recommends plywood meet or exceed PS 1 ("Construction and Industrial Plywood") - Minimum 4-ply, ⅝" nominal (19/32" actual) for 16" rafter spacing - Minimum 4-ply, ¾" nominal (23/32" actual) for 24" rafter spacing - End joints must be staggered and centered over supporting members (except tongue-and-groove)

Louisiana Roofing, Sheet Metal & Siding Exam — 36% of Exam (18 Questions)

Key Concepts

Asphalt Shingles

• Three types: Strip (3-tab), laminated/architectural (dimensional), and premium shingles. Exam focuses on architectural laminated as the standard.
• Underlayment configurations: Single layer mechanically attached; double layer mechanically attached (each course lapped minimum half the sheet width + 1 inch); single layer self-adhering (polymer-modified bitumen over entire deck); taped deck + single mechanically attached layer (minimum 4-inch-wide ASTM D1970-compliant self-adhering tape over all sheathing joints).
• Re-cover vs. replacement: Tear-off and replacement = treated as new construction. Re-cover = new covering over existing without removal.
• Underlayment functions: Temporary weather protection, secondary weatherproofing barrier, separation layer, code compliance, fire rating maintenance, and warranty compliance.

Underlayment Materials

• Asphalt felts: Organic mat, inorganic mat, or combination reinforcement. Traditional standard.
• Synthetic sheets: Lighter, higher tear resistance, faster install.
• Self-adhering polymer-modified bitumen sheets: Full-deck application; acts as vapor retarder — designers must account for moisture vapor transport.
• Self-adhering flashing tapes: Minimum ASTM D1970-compliant; used at deck joints in taped-deck configuration.

Louisiana Roofing, Sheet Metal & Siding Exam | 10 Questions | 20% of Exam

Key Concepts

Asphalt Shingles

• UL 790 / ASTM E108: Fire resistance ratings — Class A (best), Class B, Class C. Class A withstands severe fire exposure.
• UL 997 / ASTM D3161: Wind resistance ratings. Class F = 110 mph; Class H = 150 mph.
• Three main types: 3-tab (strip), architectural/dimensional (laminated), and premium/designer shingles.
• NRCA recommends direct attachment only to structural wood panel decks (plywood/OSB), wood planks, or wood boards. Do NOT attach directly to gypsum, concrete planks, or cementitious wood fiber.

Roof Deck / Sheathing (Steep-Slope)

• Deck must be clean, dry, smooth, free of voids, and adequately attached before roofing begins.
• End joints of adjacent decking must be staggered and centered over supporting members (except tongue-and-groove).
• Deck must resist excessive deflection under live loads and provide adequate fastener withdrawal resistance.

Underlayment Configurations

• Single layer mechanically attached: One layer fastened to deck with fasteners.
• Double layer mechanically attached: Each course lapped minimum half the sheet width plus 1 inch over the preceding course, applied in shingle fashion.
• Single layer self-adhering: One layer of polymer-modified bitumen self-adhering sheet over entire deck.
• Taped deck + single layer mechanically attached: Minimum 4-inch-wide ASTM D1970-compliant self-adhering flashing tape applied over all sheathing joints first, then one layer…

29 CFR 1926 | 5 Questions | 10% of Exam

Key Concepts

Fall Protection (29 CFR 1926 Subpart M)

• Low-slope roofs (≤4:12 pitch): Use guardrail systems, safety net systems, or personal fall arrest systems (PFAS). Alternatively, a warning line system + safety monitoring system is permitted.
• Steep roofs (>4:12 pitch): Must use guardrail systems with toeboards, safety net systems, or PFAS. Warning line systems alone are not sufficient.
• Fall protection required at 6 feet above a lower level on construction sites.
• Warning lines must be set at least 6 feet from the roof edge (15 feet when using mechanical equipment).

Personal Fall Arrest Systems (PFAS) – 29 CFR 1926.502(d)

• Components: Body harness, lanyard, deceleration device, anchorage point.
• Anchorage strength: Must support at least 5,000 lbs per employee attached, or be designed by a qualified person with a safety factor of 2.
• Free fall limit: Must not exceed 6 feet; worker must not contact lower level.
• Deceleration distance: Maximum 3.5 feet.
• Snap hooks: Must be locking type; no "rollout" connections permitted.
• After a fall arrest event, the system must be removed from service and inspected before reuse.

Key Concepts

Reroofing Terminology (NRCA Steep-Slope Manual, Chapter 6)

• Reroofing: The overall process — includes either re-covering OR tear-off and replacement
• Re-covering: Installing a new roof covering over an existing one without removing it
• Replacement (Tear-off): Removing the existing covering, repairing the substrate, then installing new covering
• Roof System vs. Roof Assembly: A roof system = primary covering + underlayment + insulation above deck. A roof assembly = structural deck + roof system combined

Evaluation of Existing Roof Systems (NRCA Ch. 6.2)

A proper evaluation has four parts (order is flexible, but all are required): 1. Interior inspection — underside of roof deck, evidence of active/past leakage, staining, mold, rot 2. Perimeter inspection — fascia, soffits, gutters, wall-to-roof intersections 3. Rooftop inspection — existing covering condition, flashings, penetrations, drainage 4. Other potential leak sources — HVAC, vents, skylights, chimneys

Review all available documentation first: specs, warranty, repair history, attic ventilation config, flashing details, deck type, and roof age.

Deck Condition & Moisture Detection

• Core cuts: Physical samples taken from the roof to check for wet insulation or saturated substrate
• Infrared (IR) thermography: Nondestructive; detects trapped moisture by temperature differential — most effective after sunset or before sunrise
• Nuclear/capacitance meters: Additional nondestructive testing (NDT) options
• Deck must be structurally sound, dry, and free of major defects before re-covering is approved