Read the damage first
A slow spreading ring, a fast drip, water arriving during rain or two hours after it stops — each points somewhere different, and all of it is visible from inside before anyone goes up.
Roof Leak Repair
Roof Leak Repair in Washington Township, NJ
A leak has two ends. Everyone can see the one on your ceiling; the job is finding the other one, which is usually uphill and often on a different plane of the roof entirely.
Why the obvious answer is usually wrong
Gravity does not move water straight down through a roof assembly. It runs it along the top edge of a rafter, across the underside of the sheathing, around an obstruction, and releases it wherever it meets a fastener or a seam. By the time it marks plaster, the distance between the opening and the stain can be several feet horizontally and a slope away vertically. Sealing above the stain is therefore a coin toss, and it is the reason "fixed" leaks reappear.
The sequence we work through
Get into the attic
Where there is a hatch, the underside of the deck is the most useful surface in the building. Daylight, rust rings on nail points, tide marks down the sheathing and compressed wet insulation all mark the route.
Work the roof in failure order
Anything that makes a hole gets checked first, then the metal details, then the channels that carry the most water, then the cap, and last of all whatever somebody has already had a go at. The order is just frequency of guilt.
Flood test if needed
Where nothing presents itself, water applied in sections from the lowest point upward, with somebody inside watching, until the leak reproduces.
What you get, including when we fail
A found leak comes with two photographs that obviously belong together — the opening and the damage — and a price for closing it. An unfound leak comes with an honest account of where we looked and what we ruled out, and no invoice for a guess. The second outcome is rare and it is still a better result than a sealed patch that holds until the next heavy rain.
Get it closed before the deck is involved
One wet season is a repair. Two is usually sheathing as well.