A roof inspection is one of the most critical steps in any real estate transaction—missing structural damage or water intrusion can cost you tens of thousands in repairs down the line. Before hiring an inspector or purchasing a property, knowing what a thorough evaluation actually covers will help you spot red flags and ask the right questions. This checklist breaks down exactly what professional inspectors should examine on your roof.
External Roof Surface Assessment
The inspector should start by examining the roof's surface condition from the ground and, when safe, from above. They'll look for:
- Missing, cracked, or curling shingles (especially common in roofs over 15–20 years old)
- Bald spots where granules have worn away
- Sagging sections that indicate structural failure underneath
- Flashing damage around chimneys, vents, and skylights
- Evidence of patching or repair work that may hide deeper issues
A typical residential inspection costs $150–$400, depending on roof size and complexity. Larger homes or multi-story structures may reach $500+. Inspectors should photograph problem areas and note the approximate age of the roof—this helps you estimate remaining useful life.
Gutters, Downspouts, and Water Management
Poor drainage accelerates roof deterioration and foundation problems. The inspector must evaluate:
- Gutter attachment and slope toward downspouts
- Debris accumulation and standing water
- Downspout placement and whether water drains away from the foundation (ideally 4–6 feet minimum)
- Signs of overflow or water pooling on the roof
If gutters are clogged or improperly pitched, water backs up under shingles, leading to rot and leaks that spread into the attic and walls.
Attic and Ventilation Inspection
This is where many amateur inspections fall short. A qualified inspector will climb into the attic to check:
- Adequate ventilation (soffit, ridge, and gable vents free of obstruction)
- Signs of active leaks, water stains, or mold
- Roof decking condition—soft spots indicate rot
- Proper insulation levels (R-value requirements vary by climate)
- Presence of ice dam damage in colder regions
Poor ventilation traps moisture and heat, shortening shingle life significantly. If you see black mold or dark water stains in the attic, that's a major red flag requiring further investigation.
Flashing and Penetrations
Every place where something pierces the roof (chimney, vent pipes, satellite dishes) is a potential leak source. Inspectors should verify:
- Flashing is properly sealed and not rusted or corroded
- Caulk around penetrations is intact and not cracked
- No gaps between flashing and the surface it seals
- Proper overlap so water runs downward and outward
Flashing repair or replacement typically runs $200–$400 per penetration if needed later.
Roof Age, Material, and Remaining Life
The inspector's report should clearly state:
- Roof material type (asphalt shingle, metal, tile, flat membrane, etc.)
- Estimated installation date or actual age
- Expected lifespan for that material (asphalt shingles usually 15–25 years; metal roofs 40–60 years; tile 50+ years)
- Current condition rated as "good," "fair," or "poor"
This helps you budget for future replacement. A 18-year-old asphalt roof in fair condition may need replacement within 5–7 years, which should factor into your offer price on a home.
Structural Support and Decking
A thorough inspection includes assessing what's under the shingles. The inspector looks for:
- Soft or spongy areas in the decking (sign of rot from old leaks)
- Proper nailing and fastener condition
- Adequate support beams and no visible sagging
- Evidence of previous major repairs that may not have been done correctly
Red Flags That Warrant Further Investigation
Certain findings require specialist follow-up:
- Active leaks or mold in the attic
- More than 10–15% of the roof showing damage
- Roof age near or beyond manufacturer lifespan
- Evidence of improper repairs or multiple roof layers (some areas prohibit more than two layers)
- Sagging sections or structural concerns
Getting a Second Opinion
If the inspector's findings are significant or the roof is older, consider a second inspection from a roofing contractor. A contractor's assessment focuses on repair costs and practicality, complementing the general inspector's structural evaluation. This typically costs $100–$200 and provides peace of mind.
If you're comparing inspectors and want to ensure you're hiring someone qualified, Mercoly makes it easy to find and compare trusted Structural, Roof & Foundation Inspection providers in your area.
Frequently Asked Questions
Q: How often should I have my roof inspected? Home inspections typically happen during real estate transactions, but if you own the property, annual inspections (especially after storms) help catch problems early and extend roof life.
Q: Can I walk on my roof during an inspection? Many inspectors use binoculars and drone photography to avoid unnecessary foot traffic, which can damage shingles or void warranties. Ask your inspector their approach upfront.
Q: What's the difference between a cosmetic issue and a structural one? Cosmetic issues (a few missing granules, minor algae) rarely affect function. Structural issues (rot, flashing failure, sagging) require repair to prevent water damage and further deterioration.
Use this checklist when interviewing inspectors or reviewing a report—it'll help you ask specific questions and understand what you're actually paying for.