The Cohoes chimney diagnosis I’ve written about took forty minutes on the roof. Not because forty minutes is a magic number — it’s what a proper diagnosis of a roof leak actually requires. The industry pace runs closer to four minutes and involves more of the driveway than the deck. I want to walk through exactly what a good diagnosis looks like, because if you can picture what should happen when a roofer shows up, you’ll know very quickly whether you’re getting one or not.
Before the ladder
The conversation on the porch. I ask the homeowner three things. Where is the stain. When did it show up. What was the weather like when it first appeared. Those three questions narrow the diagnosis significantly before I’ve climbed anything.
A walk of the perimeter. I look up at the roof from every side of the house. I’m looking for anything obvious — missing shingles, lifted tabs, damaged flashings at chimneys or skylights, sagging fascia, gutter issues, tree contact overhead. Sometimes the leak announces itself from ground level. Not often, but sometimes.
The attic first. If I can safely access the attic, that’s where I start. Flashlight, in daylight if possible. I locate the ceiling stain from below, then work upward — looking at the underside of the sheathing along that area for water staining, wet insulation, or visible daylight. I trace whatever I find back toward the peak of the roof, because water travels along rafters and can enter the roof plane six or twelve feet from where it emerges inside.
I take photos as I go. Not for marketing. For diagnosis. Comparing what I see in the attic to what I find on the roof is the whole point.
On the roof
Walk the primary suspect area first. If the attic pointed me toward a specific area — under a chimney, near a plumbing vent, at a valley — I start there. Lift shingles where I need to. Look at the flashing detail. Check the surrounding sealant. Look for step flashing failures or counter-flashing gaps.
Check every roof penetration on the whole roof. Even if I’ve found the leak at the first flashing, I look at all of them. Chimneys, skylights, plumbing vents, satellite mounts, gable vents. Because a house that has one flashing failing is often a house with others that are about to. Better to catch them now than come back in six months.
Walk the field for shingle condition. I look at the shingle field on every slope. Color uniformity. Granule coverage. Curling at the tabs. Cracking on the exposed surfaces. Nail-pop deterioration. This is where I decide whether we’re looking at a targeted repair or the beginning of a shingle-field failure.
Check the valleys. Debris trapping water. Signs of long-term water flow. Wear patterns in the shielding. Ice dam damage from previous winters.
Check the eaves. Ice-and-water shield age. Fascia condition. Gutter attachment and pitch. Any sign that eave-side ice damming has been an ongoing issue.
Check the ridge. Ridge vent sitting flush. Any lifting or damage from wind. Cap shingle condition.
Open a downspout for the granule test. I’ve written about the granule test elsewhere. Same test on repair jobs — I want to know whether the shingle material is aging out even if the immediate leak is a flashing failure.
The photography step
I photograph everything relevant. Before, during if I lifted anything, after. The photos serve three purposes:
Diagnosis documentation. I want to show the homeowner what I saw. Not describe it — show it. If I found a counter-flashing pulled away from the brick, they see the photograph and understand the problem. This is what makes a diagnosis-first process transparent.
Warranty baseline. If I later need to defend the state of the roof at the time of my diagnosis — for a warranty claim, an insurance discussion, or anything else — the photos are the record.
Insurance claim support. If the leak turns out to be tied to a storm event and there’s an insurance claim, the documented pre-existing condition of the surrounding roof is what allows the adjuster to distinguish storm damage from wear.
Coming back down
After the roof walk, I go back through the attic one more time if the roof exam raised new questions. Then I sit down with the homeowner — usually at the kitchen table — and go through what I found.
What’s causing the leak. Specific. Named. Photographed.
What the repair actually needs to include. Scope, materials, timeline, cost range.
What I saw that isn’t the leak but is worth mentioning. A pipe boot that’s got three or four years left in it. A flashing that’s not failing yet but is getting close. A ventilation situation that could be improved. Not upsells — information.
What the roof’s overall condition is. So the homeowner knows whether they’re doing spot repairs on a mostly-sound roof or whether the repair is buying time on a roof that’s going to need replacement in the next five years anyway.
What we can guarantee. Three years written on the repair. What that covers, what it doesn’t.
That’s the conversation. That’s what a diagnosis looks like. The whole thing, from arrival to written quote, usually takes about an hour and a half on a mid-sized roof.
What you should get in writing
Before any repair work happens, you should have:
– A written diagnosis of the specific cause of the leak – Photographs supporting the diagnosis – A written scope of what the repair will and won’t include – A cost figure that isn’t going to change unless we find something under the surface (and if we do, we tell you before we do the extra work, not after) – A written warranty on the repair
Anything less than that is somebody selling you a service, not diagnosing your roof.
Paul Sandul, Elite Contracting. Family-owned. Clifton Park.
The full story of what a diagnosis-first process looks like in practice is in our pillar: The Cohoes Chimney Drip. Service page: Roof Repair.