The four roof leaks we see most in Mobile County — and how to catch them early

Across hundreds of repair calls in Mobile and Baldwin County, four leak types account for almost every one we fix. They're not random. They show up in the same places, on the same kinds of roofs, at roughly the same age — and most of them are catchable from the ground if you know what to look for.

Here are the four leak types we see most, how to spot each one before the ceiling stain shows up, and when it's time to call.

Leak 1 — pipe boot cracks

Every plumbing vent on your roof has a pipe boot — a metal flashing base with a rubber gasket that wraps around the pipe and seals against water. The rubber gasket is the weak link. In Gulf Coast heat, that rubber dries out, cracks, and pulls away from the pipe somewhere between year eight and year twelve. Once it cracks, water runs straight down the pipe into the attic.

How to spot it from the ground. Grab binoculars and look at every vent pipe on the roof. The rubber boot sits at the base of the pipe. If it looks cracked, pulled away, or has a visible gap, that's the source. UV does the damage from above; you can usually see it without climbing.

Ceiling pattern that hints at it. A round or oval stain in the ceiling, often near a bathroom or a kitchen. Pipe boots are above plumbing fixtures, so the stain lands above the bathroom or kitchen below it. The stain tends to grow slowly over days or weeks of rain.

Repair scope. Pull the old boot, install a new one with the modern lead-and-EPDM design (or all-metal coastal-grade for homes within a mile of the water), and seal it into the surrounding shingles. About an hour of work per boot.

Leak 2 — chimney and skylight flashing

Where the roof meets a vertical surface — chimney, skylight curb, sidewall, dormer — there has to be flashing. Step flashing along the sides, headwall flashing across the top, and a cricket (a small peaked structure) behind chimneys wider than 30 inches. Flashing failure here is the second-most-common leak we see.

How to spot it. Look at the chimney from the ground. Is the flashing folded into the brick joint (good) or just sitting against the brick with sealant (bad)? Are there gaps, rust, or visible separation? Same for skylights — look around the perimeter where the curb meets the shingles.

Ceiling pattern. A stain near or directly below the chimney or skylight. Sometimes the stain shows up along an interior wall that connects to the chimney chase. The leak follows the framing — so the stain may appear several feet from the actual entry point.

Repair scope. New step flashing, new counter flashing folded into a fresh cut in the brick joint, fresh sealant. On wide chimneys with no cricket, we add one — water can't pond behind a chimney if it has somewhere to go.

Leak 3 — valley wear

A valley is the V-shaped junction between two slopes that meet at an internal angle. Water from both slopes runs down the valley to the gutter. Volume is high. So is wear.

Two failure modes show up here. First, leaves and debris collect in the valley and dam up the water — instead of running off, water pools and works its way under the shingles. Second, the valley metal or the woven shingle pattern wears thin from the constant scouring of water and granules.

How to spot it. Look at the valleys from the ground. Are they clean? Is debris collecting at the bottom near the gutter? Can you see worn-down spots in the valley metal or shingle? After a heavy rain, watch how the water exits the valley — if it backs up rather than flows freely, there's a blockage.

Ceiling pattern. A stain along an interior wall or ceiling that runs parallel to the valley above. Often shows up only during the heaviest rain events.

Repair scope. Clear the valley, inspect the underlying metal or membrane, replace any worn shingles or flashing, and add ice-and-water shield underneath if it wasn't there from the original install. For severely worn valleys, we replace the full valley assembly.

Leak 4 — nail pops and missing shingles after wind

Gulf Coast wind events lift shingles, pop nails through the shingle face, and tear tabs along the edges. None of these failures show up as a dramatic hole — they show up as small breaches that take their own time to leak.

How to spot it. After any wind event over 40 mph, walk the perimeter of the house and look at the roof. Are any shingles missing tabs? Are any tabs lifted (curled up)? Can you see exposed nails where a shingle was supposed to cover them? Walk the yard and gutters too — shingle pieces in the lawn or granules washed out into the gutters are tells.

Ceiling pattern. Often spreads — a small stain first, then more as the next rain finds the same breach. Wind damage rarely produces a dramatic drip on day one. It builds.

Repair scope. Re-set or replace popped nails, replace missing shingles with matched material, reseal lifted tabs, and inspect surrounding fasteners for the same failure. Wind events tend to damage adjacent shingles even when only one is visibly affected.

When to call us

Some homeowners wait until water is dripping into a light fixture before they call. By then, drywall is wet, insulation is wet, framing is wet, and what would have been a $300 boot replacement is now a $3,000 interior repair plus the roof work.

Call when you see any of these:

• A stain on a ceiling, no matter how small, that grows after rain
• Daylight visible through the roof deck when you're in the attic
• Granules collecting in your gutters in unusual amounts (some loss is normal; piles aren't)
• Missing shingle tabs you can see from the ground
• A lifted, curled, or detached ridge cap shingle along the peak of the roof
• A musty or moldy smell from the attic — water has been there long enough to start growing things

Maintenance schedule we recommend

Two roof inspections a year is the right cadence on the Gulf Coast. We recommend:

• After every named storm. Wind events do damage even when the storm wasn't a direct hit.
• Once each fall. Pre-winter check, after the summer heat has done its work on rubber boots and sealants.

Our free roof check covers both. We climb the roof, photograph everything, and write up a condition report. If we find a small problem, we quote a small repair. If everything looks good, we say so and you go on with your year.

Related reading on our site: roof repair, emergency leak repair, and storm damage response.