Chimney Leak Repair Near the Lake and Inland

Lake Michigan makes its own weather. On November 9 and 10, 2025, the National Weather Service in Chicago recorded lake-effect bands that dropped 10.0 inches on Winthrop Harbor, 5.7 inches in Chicago's West Ridge, 5.2 inches near Evanston and 5.0 inches in Gurnee, with snow falling over 2 inches an hour in parts of Lake County and thundersnow near the shore. O'Hare got 1.7 inches that same night. A chimney near the lake can be buried while one a few miles inland gets a dusting.

All of that snow melts on and around the chimney. Water finds a cracked crown, an open joint, a flue with no cap or worn flashing, and it comes out somewhere else: the firebox, the ceiling, the attic. Leak sealing typically runs $150 – $500, crown repair $150 – $700 and flashing repair $300 – $1,800. The leak evaluation is free.

Signs you need this

• Water or rusty streaks in the firebox after a storm
• A stain on the ceiling or wall next to the chimney
• A musty, damp smell from the fireplace
• White salt or peeling paint on the chimney breast inside
• A damper rusting shut or flue tile flaking

How we do it

1. Free leak evaluationWe check the cap, crown, brick, mortar and flashing, and look at where the water shows up inside.
2. Trace the pathWater usually enters well above where it appears. We match the stains inside to what we see outside.
3. Fix the entry pointCrown, flashing, joints or cap: we repair where the water gets in, priced in writing first.
4. Protect the brickWhere it helps, a breathable water repellent goes on the brick so it sheds water but still dries.

Where chimney leaks really start

We find most chimney leaks at one of five places.

• An open flue with no cap, letting rain and snow straight down
• A cracked crown or a mortar crown with no overhang
• Mortar joints open enough for water to soak into the brick
• Flashing that is rusted, loose or replaced with tar
• Brick that has lost its faces and now soaks up water

Lake-effect snow and the north side of the metro

The NWS noted that the November 2025 bands left a gap over Chicago and nearby suburbs while hammering Lake County, and after a February 2019 storm it reported the highest totals in Lake County and northern Cook once lake-effect snow was added. Lake-effect snow doesn't hit the same towns every winter, but chimneys along the lake take it more often and in heavier doses. Wind off the water also drives rain sideways into the brick on the side facing the lake.

So a north-shore chimney often leaks through the brick and joints, not just at the flashing. That is why we check the whole stack.

Waterproofing that lets the brick breathe

Once the entry points are fixed, a breathable water repellent can help brick that soaks up water. It must let water vapor out, or moisture gets trapped behind the surface and freezes there. Breathable waterproofing typically runs $150 – $820+. We don't recommend coating brick that still has open joints or a cracked crown; fix those first.

Leaks and selling a house

Item 6 on the Illinois Residential Real Property Disclosure Report asks sellers about leaks or material defects in the roof, ceilings or chimney. If you're selling, fixing a known leak and having photos of the repair is simpler than explaining it.