Yes. Ice that builds up on the roof can back meltwater up behind the chimney flashing or into weak spots in the masonry, which shows up as stains inside the house after a thaw. Fixing a leak around the chimney in Boston typically costs $400 to $3,000, depending on what the inspection finds as the source.
How an ice dam forms near a chimney
An ice dam is a ridge of ice that forms along the lower edge of a roof. Snow on the upper roof melts, runs down to the colder edge and refreezes. The ice grows into a wall, and the water behind it has nowhere to go. It backs up under shingles and finds its way inside.
A chimney makes the problem worse in two ways. First, the chimney is a wall that sits across the slope of the roof, so snow and meltwater collect on the uphill side. Second, the roof joint around it, with flashing and sealant, is one of the most likely places for water to enter. A little standing water or ice there can push into gaps that rain alone would never reach.
Boston's mix of snowstorms, thaws and refreezes, plus nor'easters with wet snow, gives these conditions to older homes and new ones alike.
Signs the leak follows snowmelt
A leak caused by an ice dam has a pattern. Rain leaks usually appear during or just after a storm. Ice dam leaks tend to show up when the snow is melting, often on a sunny day after a cold spell, or when temperatures swing above and below freezing.
- Water stains on the ceiling or wall next to the chimney breast
- Drips that start on a sunny afternoon, even though it is not raining
- Icicles hanging from the roof edge or ice built up beside the chimney
- Peeling paint, bubbling plaster or damp insulation in the attic around the chimney
- Efflorescence, a white powder, on the brick or damp patches inside the fireplace
Write down the date and the weather each time you see a stain. That record is useful when the technician sorts out the cause. If it also leaks during rain, there may be more than one source. Our post on a chimney leaking when it rains covers the rain version.
Not every stain is an ice dam
A ceiling stain near the chimney can have several causes. It might be ice melt, a roof leak elsewhere that runs along a rafter, condensation in a cold flue, or failed flashing that leaks in any wet weather. Assuming it is the ice dam can mean the real cause stays hidden.
| Cause | When it shows up |
|---|---|
| Ice dam backing up water | During thaws after snow |
| Failed flashing or sealant | In rain and snowmelt |
| Cracked crown or open mortar | After wet weather, often slow |
| Condensation in the flue | In cold weather, often with a damp smell |
| Roof leak away from the chimney | In rain, sometimes far from the stack |
Because several of these can look alike, a documented inspection is better than a guess. The technician looks at the chimney, the roof joint and the attic where it can be done safely, and notes what the evidence supports.
The parts that fail first
When ice or meltwater pushes at a chimney, a handful of components take the hit.
- Step and counter flashing. Metal pieces that seal the joint between roof and chimney. If they are lifted, rusted or sealed with only caulk, water gets behind them.
- Back pan and cricket. A cricket is a small peaked structure behind the chimney that splits water around it. Without one, snow and water pile up uphill of the stack.
- Mortar joints and brick. Water soaked into the brick freezes and breaks the surface apart, a problem known as spalling.
- The crown. A cracked crown lets water in from above. See chimney crown repair.
Look at our chimney flashing repair cost page for how flashing work is priced.
Why wide chimneys suffer more
The wider the chimney, the more snow and ice it holds back on its uphill side. A wide stack on a steep roof, or one near the roof edge where ice tends to form, faces more pressure on its flashing than a narrow one at the ridge. That is why a leak can appear on one side only, and why the technician checks every side of the stack, not just the one with the stain.
Roof, insulation and chimney: who handles what
Ice dams often begin with heat escaping into the attic and warming the roof from below. Poor insulation, air leaks and ventilation problems can all contribute. Those are roofing and insulation issues, and a chimney company does not fix them.
Where the chimney meets the roof, the lines blur. The chimney technician handles the flashing, the cricket and the masonry. A roofer handles shingles, underlayment and the roof deck. An insulation or energy specialist handles attic air sealing.
Tell each contractor what the others found, and share the photos. If you can, let one person see the whole picture before work begins, so repairs are not done twice. We can write our findings by location, so a roofer knows exactly what to look at and what we covered.
Check with your insurance agent about coverage for water damage from ice. We cannot say what any policy covers, and your records of dates, photos and the written price will help.
What the repair costs
The range for chimney leak repair in Boston is $400 to $3,000. The number depends on where the water is getting in, and the technician names the source after the inspection. These are the common items:
| Repair | Typical Boston price |
|---|---|
| Flashing repair | $200 to $400 |
| Partial flashing | $400 to $800 |
| Full flashing | $800 to $2,500 |
| Crown repair | $300 to $900 |
| Waterproofing, standard | $300 to $500 |
| Repointing, partial | $300 to $700 |
Waterproofing is a protective treatment, not a cure for a failed flashing. It works best after the leak source is fixed. Learn more about chimney leak repair and how each fix is scoped.
A cricket or a rebuilt roof joint belongs to a larger scope, quoted in writing after the inspection.
What to do before and after the next thaw
There is a lot you can do without leaving the ground.
- Photograph any ice, icicles and stains with the date
- Place a bucket or towels under a drip, and move valuables
- Do not chip at ice on the roof, and do not climb up to clear it. This damages shingles and is dangerous
- Check the attic if you can do so safely from the access hatch, for damp insulation near the chimney
- Do not use a fireplace if water is running into the firebox, until it has been checked
Then schedule the inspection for a time when the roof is safe to work on. Booking the $49 inspection, credited toward approved repair work, takes a call to (617) 404-9587 or the form at /contact/.
Questions homeowners ask
Should I remove ice dams from around the chimney myself?
No. Chipping ice can damage shingles and flashing, and roof work in winter is dangerous. Photograph it and have it assessed. If water is entering the house, protect the room and call a professional.
Will fixing the flashing stop ice dam leaks for good?
Not always. If heat loss from the attic is causing ice to build, flashing repair alone may not stop it. The technician can report what they find, and you may need a roofer or an insulation specialist too.
Why does my ceiling only leak when the snow melts?
Meltwater can back up behind ice and reach gaps that rain does not. It also flows slowly, so a stain may appear hours after the thaw begins. Track the dates and the weather.
Can ice damage the brick of the chimney itself?
Yes. Water that soaks into brick and mortar expands when it freezes, which can crack or flake the surface. Repointing or repair can follow. Our guide to freeze-thaw damage has more.
Does homeowners insurance cover ice dam damage?
Coverage depends on your policy, and we cannot tell you what yours says. Contact your agent, keep photos with dates, and keep any written price you receive.