Roof Inspection Checklist: Seattle Homeowner’s Guide

Your roof takes more punishment in Seattle than almost anywhere else in the country. Months of steady rain, moss that grows on anything that holds still, and freeze-thaw cycles in winter all work against it. A good roof inspection checklist for Seattle homeowners catches small problems while they are still small, and that is the difference between a modest repair and a soaked attic.

We are Bullock Builders, a family-owned Seattle contractor, and roofing is our most active line of work. Our in-house roofers see the same failure patterns over and over, so we built this checklist around what actually goes wrong on Northwest roofs. Use it twice a year, ideally in early fall before the heavy rain and again in spring.

DIY Inspection vs. Professional Inspection

You can do a lot from the ground and from inside your attic. Binoculars, a flashlight, and thirty minutes will reveal most developing problems. What we do not recommend is homeowners walking their own roofs. Wet Northwest roofs are slick, moss makes them slicker, and a fall is not worth the ladder trip.

A professional inspection adds what the ground view cannot: close checks of flashing, fastener condition, sealant, and the subtle soft spots that signal decking damage. Our rule of thumb is simple. Do a DIY check twice a year, and bring in a professional roofing contractor every 2–3 years, after any major windstorm, or the moment you see interior staining.

Signs of Roof Damage in Seattle’s Climate

Start from the ground with binoculars and work through this list:

• Curling, cupped, or cracked shingles. Asphalt shingles at the end of their life deform before they fail.
• Missing shingles or exposed underlayment. Common after our fall and winter windstorms, especially on ridge lines and edges.
• Granule loss. Check gutters and downspout splash areas for accumulating granules, which mean shingles are wearing out.
• Sagging roof planes. A dip in the roof line suggests decking or structural trouble underneath. Do not wait on this one.
• Rust streaks or stains. Often traced to failing fasteners or flashing above the stain.
• Damaged or lifted ridge caps. Ridge lines take the most wind and fail first.

Moss and Algae: The Pacific Northwest Problem

Moss is not cosmetic. It holds water against the roof surface, works under shingle edges, and pries them up as it grows. On north-facing slopes and under tree cover, moss can shorten a roof’s life by years.

What to look for:

• Green growth along shingle edges and in shaded valleys
• Black algae streaking, which is mostly cosmetic but worth noting
• Lifted shingle edges where moss has grown underneath

What we recommend: keep trees trimmed back, clear debris from valleys, and treat moss with roof-safe products. Do not pressure wash an asphalt roof. It strips granules and ages the roof faster than the moss would have. Our roofing maintenance guide covers safe moss treatment in more detail.

Leak Detection: Find Water Before It Finds Drywall

Water rarely drips straight down from its entry point. It travels along rafters and sheathing, which is why leaks show up far from their source. Check these spots:

• Ceiling stains, especially rings that grow after storms
• Peeling paint or bubbling drywall on upper-floor ceilings and walls
• Musty smells in closets and corners of upper rooms
• Water marks around skylights, chimneys, and bath fan penetrations

A good trick: check ceilings during or right after a hard rain, then again a day later. Fresh stains that darken during rain point to an active leak rather than an old repaired one.

Flashing: Where Most Roofs Actually Fail

In our experience, flashing failures cause more Seattle leaks than shingle failures. Flashing is the metal that seals every transition: chimneys, skylights, valleys, sidewalls, and vent pipes. Inspect for:

• Rust, gaps, or lifted edges on chimney and skylight flashing
• Cracked or shrunken sealant around vent boots
• Valley metal with debris dams that push water sideways under shingles
• Sidewall flashing where the roof meets an upper wall, a classic hidden failure point

Flashing work is detail work, and it is where cheap roofing jobs cut corners. When we replace a roof, flashing and moisture management get engineered properly for this climate, because that is what keeps a roof watertight for decades.

Gutters and Drainage

Gutters are part of your roof system, and in Seattle they work overtime. Check that:

• Gutters are clear of needles and leaves, especially before November
• Downspouts discharge away from the foundation
• There are no sagging sections or separated seams
• Water is not overshooting the gutter during hard rain, which suggests a blockage or pitch problem

Overflowing gutters do not just rot fascia boards. They dump water against siding and foundations, turning a roof maintenance issue into a much bigger repair.

Attic Warning Signs

The attic tells you the truth about your roof. With a flashlight, look for:

• Dark stains or streaks on the underside of the sheathing
• Damp, matted, or moldy insulation
• Daylight showing through the roof deck anywhere except vents
• Rusted nail tips, which indicate chronic condensation
• Blocked soffit vents or a stuffy, humid feel

Ventilation matters as much as leaks here. A poorly vented attic traps moisture that condenses on cold sheathing all winter, rotting the roof from below. Guidance from the U.S. Department of Energy on attic ventilation and insulation is a useful starting point, and we evaluate ventilation on every roof project we take on.

Repair or Replace: Our Honest Take

Not every problem means a new roof, and we will tell you honestly which side of the line you are on. When a repair is enough, we’ll say so.

Repair usually makes sense when: damage is isolated to one area, flashing is the culprit, the roof is under 15 years old, and the decking underneath is sound.

Replacement is usually the better investment when: shingles are failing across multiple slopes, the roof is at or past its expected life, repairs are becoming a yearly event, or leaks have damaged decking. Patching a worn-out roof is spending good money on borrowed time.

When replacement is the answer, it is faster than most people expect. Our in-house crews complete most full roof replacements in 2–5 days, in asphalt shingle, metal, or cedar shake. Every project follows our six-step process with one project lead, photo documentation, and a clean job site.

Frequently Asked Questions

How often should I have my roof inspected in Seattle?

Do a ground-level and attic check yourself twice a year, in early fall and spring. Add a professional inspection every 2–3 years, after any major windstorm, and immediately if you see interior water stains. Seattle’s wet season is long, so fall timing matters most.

Is moss on my roof really a big deal?

Yes. Moss holds moisture against shingles and lifts their edges, which lets wind-driven rain get underneath. Left alone, it shortens roof life significantly, especially on shaded north-facing slopes. Treat it early with roof-safe methods and never pressure wash asphalt shingles.

How do I know if a stain on my ceiling is an active leak?

Watch it through a rain cycle. Mark the stain’s edge with pencil, then check during and after the next hard rain. If it grows or darkens, the leak is active. Either way, have it inspected, because even a dried stain means water got past the roof at some point.

What does a professional roof inspection include?

We check shingles, ridge lines, flashing at every penetration, valleys, gutters, ventilation, and accessible attic spaces, then document what we find with photos. You get a straightforward report and an honest recommendation. If the roof just needs maintenance, that is what we will tell you. More answers are on our FAQ page.

Schedule a Professional Roof Inspection

If this checklist turned up anything questionable, or if your roof simply has not been looked at in a few years, let us take a look before the wet season does its worst. We offer free estimates, fast responses, and honest advice about what your roof actually needs, no more, no less.

Contact Bullock Builders or book an appointment online. You can also call or text (206) 802-8110. A thirty-minute inspection now beats a soaked ceiling in January.

References

• U.S. Department of Energy, Energy Saver guidance on attic insulation and ventilation: energy.gov/energysaver