Stains on the ceiling beside the chimney
The most common sign of failed flashing.
Chimney flashing and crown repair in New York, NY
A chimney is a hole in the roof surrounded by brick that moves differently from everything around it. When its flashing, crown or joints fail, water runs down beside the flue and into the rooms below.
- We answer 24/7
- Step and counter flashing
- Crowns and repointing
Quick answer: Chimney leaks in New York, NY usually come from failed step or counter flashing where brick meets roof, a cracked crown on top of the chimney, or open mortar joints above the roofline. Repair means reflashing the chimney properly, sealing or rebuilding the crown, and repointing the brick above the roof.
What the job involves
Three places a chimney lets water in
At the roofline, step flashing runs under each course of shingles up the sides of the chimney, and counter flashing set into the mortar joints laps over it. On a flat roof, membrane base flashing wraps the chimney with metal counter flashing above. Either fails when sealant has been used in place of proper metal laps.
Higher up, the crown around the flue cracks and lets water into the chimney's core, and open joints soak water into the brick itself. A leak beside a chimney can come from any of the three, so each is checked before anything is sealed.
Cost factors
What chimney repair costs depend on
Flashing type
Step and counter flashing on shingles, or membrane and counter flashing on a flat roof.
Metal
Aluminum, coated steel or copper.
Crown condition
Sealing hairline cracks costs far less than rebuilding the crown.
Masonry
How many joints and bricks need work above the roof.
Chimney width
Wide chimneys on sloped roofs need a cricket behind them.
Height and access
Tall chimneys and steep roofs need staging.
Variations of the job
Chimney work we do
Step flashing
Individual L-shaped pieces woven into each shingle course up the sides of the chimney, so every piece sheds onto the shingle below. Missing or rusted pieces are replaced as a set, not caulked.
Chimney crown
The sloped cap around the flue. Hairline cracks can be sealed with a crown coating; a crown that is breaking up or has no overhang is rebuilt with a drip edge so water falls clear of the brick.
Repointing at the roofline
Open joints above the roof let water into the brick and behind the counter flashing. Joints are ground out and repointed with mortar that suits the brick, and counter flashing is reset into fresh joints.
Do it yourself or call
What you can check without climbing up
Safe to do yourself
- Look at the chimney from the ground with binoculars after storms.
- Check the attic or top-floor wall beside the chimney for damp after rain.
- Note whether leaks appear only in wind-driven rain or in any rain.
- Photograph stains with a date so growth is easy to see.
Leave to a roofer
- Climbing onto a pitched roof to reach the chimney.
- Smearing sealant over flashing, which hides the problem and traps water.
- Patching a crumbling crown with mortar, which cracks again quickly.
- Repointing brick at height.
Local conditions
Chimneys on Long Island shingle roofs
Asphalt shingles are by far the most common residential roof covering in New York State, and on Long Island that usually means a chimney rising through a shingle roof. That is the detail where step flashing matters most: every shingle course along the chimney needs its own piece, and shingles replaced without reweaving that flashing leave a leak waiting for the next wind-driven rain.
How it runs
How chimney repair runs
- 1
Inspect all three
Flashing, crown and joints checked, with photos.
- 2
Water test
Water run at the flashing, then the brick, to find the path.
- 3
Repair the masonry first
Repoint and rebuild the crown before new flashing.
- 4
Reflash
Step and counter flashing, or membrane and counter flashing.
- 5
Check and photograph
Water test the finished detail and send photos.
Warning signs
Signs your chimney is letting water in
Damp walls around the fireplace
Water moving down inside the masonry.
Cracks across the crown
Water getting into the chimney's core.
Rust or gaps in the metal at the roofline
Flashing near the end of its life.
Caulk smeared along the flashing
A past repair that is likely failing.
White deposits on the brick
Salts left as water works through the masonry.
Questions we hear
Chimney flashing questions
Wind-driven rain reaches the flashing and brick on one side of the chimney. Leaks that follow a particular wind direction usually point to flashing or open joints on that face.
No. Sealant dries out and cracks, and it often hides failed metal underneath. The proper repair replaces the step and counter flashing.
The sloped cap on top of the chimney around the flue. It sheds water off the top, and when it cracks, water gets into the chimney's core.
Wide chimneys on sloped roofs usually do. A cricket is a small ridge behind the chimney that splits water around it instead of letting it pool against the brick.
Not necessarily. Most leaks are at the flashing or crown. The flue liner is a separate check for a chimney professional, especially if the chimney vents a heating appliance.
Related services
Related roofing work
Bulkhead Roofing & Repair
Stair and elevator bulkheads have their own roofs, walls and door sills, and each one leaks. We roof, flash and seal them as a unit.
Learn moreSkylight Repair & Replacement
Leaking curbs, cracked domes and rusted roof hatches repaired or replaced, with the curb flashed into the roof properly.
Learn moreParapet Wall Repair
Open joints, bulging brick and failed inside-face flashing are where many top-floor leaks begin. We repoint, rebuild and reflash.
Learn moreWater showing up beside the chimney?
Call and we will check the flashing, the crown and the brick.