Module 4: Roof Repairs, Maintenance & Estimating 

This module equips roofing professionals with advanced diagnostic, repair, and planning skills to extend roof lifespan, minimize water damage, and accurately estimate project costs.

1. Leak Detection & Troubleshooting (Common Failure Points)

Roof leaks often originate from predictable areas. Systematic inspection techniques help locate and resolve issues efficiently.

Key Subtopics:

• Common Leak Locations:

• Flashing failures (chimneys, vents, skylights, wall transitions).

• Clogged or improperly installed gutters/downspouts.

• Cracked vent boots, deteriorated sealants, or missing shingles.

• Inspection Methods:

• Infrared Thermography: Identifies moisture trapped under membranes.

• Water Testing: Simulates rain to trace infiltration paths.

• Visual Checks: Blistering, granule loss, or rusted flashing.

• Attic Inspections:

• Stains, mold, or daylight visible through roof deck indicate leaks.

2. Patching & Re-Roofing Techniques (Shingle Replacement, Membrane Repairs)

Proper repair methods vary by material and damage severity.

Key Subtopics:

• Asphalt Shingle Repairs:

• Lift-and-Slide Method: Replacing individual shingles without damaging adjacent ones.

• Sealant Application: Temporarily fixes lifted shingles until replacement.

• Flat Roof Membrane Repairs:

• Patch Installation: Cutting out damaged sections and welding/seaming new material.

• Liquid Coatings: Elastomeric coatings for small cracks or blisters.

• Partial vs. Full Re-Roofing:

• Overlay Limitations: Building codes often restrict second shingle layers.

• Tear-Off Best Practices: Safe debris disposal and substrate inspection.

3. Material Estimation (Calculating Squares, Waste Factors)

Accurate estimates prevent project delays and cost overruns.

Key Subtopics:

• Measurement Basics:

• 1 Square = 100 sq. ft. (Standard roofing measurement unit).

• Slope Factor Adjustments: Steeper roofs require more material (e.g., 12/12 pitch adds ~41% surface area).

• Waste Calculation:

• 10–15% Waste Standard: Complex roofs (valleys, dormers) may need 20%.

• Membrane Rolls: Account for seam overlap (2–4 inches per roll).

• Accessory Quantities:

• Flashing, nails, underlayment, and adhesives based on roof type.

4. Reading Blueprints & Roof Plans (Slope, Drainage, Penetrations)

Interpreting construction documents ensures compliance with design intent.

Key Subtopics:

• Blueprint Symbols:

• Identify rafters, vents, drains, and HVAC penetrations.

• Slope Indicators:

• Pitch Notation (e.g., 4:12): Vertical rise per 12" horizontal run.

• Drainage Requirements: Low-slope roofs need tapered insulation or scuppers.

• Penetration Details:

• Verify flashing types/sizes for pipes, curbs, and edges.

Why This Module Matters

• Leaks cause 80% of roofing insurance claims (IBHS).

• Improper estimates lead to 5–15% budget overruns (NRCA).

• Blueprint errors result in failed inspections or structural issues.

Interactive Exercise Suggestion:

• Provide sample blueprints for trainees to calculate materials and identify leak risks.