Wellesley, MA · Norfolk County
Leak Around Chimney Flashing in Wellesley, MA
The joint where your chimney meets the roof fails before almost anything else on the house. We rebuild step and counter-flashing the right way — cut into the mortar, not smeared over it. Typical flashing repairs across Greater Boston run $400–$1,200, with full step-and-counter-flashing rebuilds on large chimneys or steep roofs pushing toward the top of that range.
Call (781) 653-5644Every autumn, searches for "leak around chimney flashing" spike across Greater Boston, and every autumn our phone at (781) 653-5644 rings with some version of the same story: the first cold night arrived, someone lit the first fire of the season, and something was clearly wrong. Chimneys have a way of announcing their problems exactly when you need them most. The good news is that most of these problems are well understood, diagnosable in a single visit, and fixable before deep winter sets in — provided you do not wait until December, when every sweep in Massachusetts is booked solid. This article from Upside Down Chimney Sweeps lays out what the issue behind your search typically is, how we confirm it, what the repair involves, and how to time the work sensibly so the fireplace is ready when the cold is.
The stakes with chimney problems are not hypothetical. A chimney's core function is containment: keeping flue gases, sparks, and extreme heat inside a sealed passage until they exit above the roof. Carbon monoxide is odorless and colorless, and a blocked or leaking flue can push it back into living space instead of venting it outside. Meanwhile, creosote — the tar-like residue wood smoke deposits inside the flue — is fuel waiting for an ignition source, and chimney fires often burn unnoticed until they have damaged the liner or spread toward framing. This is why both NFPA 211 and CSIA guidance treat annual inspection as a baseline, not an upsell. Most chimney issues are discovered during a routine visit, long before they become emergencies. The dangerous ones are almost always the ones nobody was looking at.
Chimneys hide their problems better than almost any other part of a house. The flue interior is invisible without a camera. The crown is above the roofline where nobody looks. Flashing failures leak into wall cavities and show up as mysterious stains rooms away from the chimney. Even serious creosote accumulation is out of sight the moment you step back from the firebox. This is why homeowners are so often blindsided — not because they were careless, but because the evidence was structurally concealed. It is also why the chimney trade leans so heavily on scheduled inspections rather than wait-for-symptoms maintenance. By the time a chimney problem is visible from the living room, it has usually been developing for years. The search that brought you here may be the first visible edge of something older.
Chimney Flashing Repair in Wellesley, MA
A correct installation has distinct layers with distinct jobs. Step flashing consists of L-shaped pieces of metal, one woven into each course of shingles as the roof climbs past the chimney, so every piece hands water down onto the shingle below it. Counter-flashing is the second layer: metal let into a groove — a reglet — cut into the chimney's mortar joints, then bent down over the tops of the step pieces. This counter-stepped arrangement means water running down the brick face is thrown out over the steps, never behind them, and neither layer depends on adhesive to do its job. An apron protects the downhill face, and on the uphill side a back pan or cricket diverts the water the chimney dams up.
Upside Down Chimney Sweeps rebuilds and repairs chimney flashing across Wellesley and the surrounding Greater Boston area from our home base in Melrose. We work both sides of the joint — mason enough to cut and repoint reglets correctly, roof-literate enough to weave steps into shingle courses without wrecking the field around them. Flashing sits exactly at the boundary where roofers and masons tend to point at each other; we take responsibility for the whole intersection instead. If you have stains near the chimney, a visible tar patch on the roof, or a roofer who told you the chimney is the problem, call (781) 653-5644 and we will get experienced eyes on it.
Around Boston, flashing dies in predictable ways. Galvanized steel rusts through — faster near the coast, where salt air is relentless. Counter-flashing that was surface-mounted with caulk instead of cut into the mortar peels away as the sealant fails. Nails back out of step flashing as the decking flexes through the seasons. Ice dams push meltwater up-slope and sideways, finding laps that shed downhill flow perfectly well. And on a remarkable number of roofs we inspect, someone has already answered a leak with roofing cement — a repair that buys a season or two, traps water behind it, and makes the eventual proper repair messier. If your chimney wears a black tar collar, water has been in there before.
What the Service Includes
1Full flashing evaluation
We inspect the entire roof-to-chimney intersection from both sides: on the roof, we check step flashing engagement, counter-flashing seating, apron condition, fastener back-out, and any previous tar or caulk repairs; in the attic, we examine the sheathing and rafters around the chase for staining, delamination, and active moisture with a meter. Because flashing failures mimic crown and masonry leaks, we rule those out rather than assume. You get photos of everything and a straight answer about whether flashing is truly your problem — sometimes it is not, and we say so.
2Step flashing replacement
When steps are rusted, missing, or face-nailed through their vertical legs, we replace them properly. Shingle courses alongside the chimney are carefully lifted or removed, the old metal comes out, and new L-shaped steps go in — one per course, each overlapping the piece below, fastened to the deck rather than the masonry so the roof can move freely. Where conditions warrant, we bed the intersection in self-adhering ice-and-water membrane first, which matters enormously on the snow-loaded, ice-dam-prone rooflines common across Massachusetts.
3Counter-flashing cut into the mortar
This is the detail that separates a proper job from a caulk job. We grind a clean reglet into the mortar joints, following the joint line up the chimney in steps, insert the counter-flashing's bent edge into the groove, wedge it mechanically, and seal the joint with the right sealant — used as a gasket inside a groove, not as glue on a surface. Counter-flashing installed this way is held by the chimney itself and sheds water over the step flashing below it for decades.
4Crickets and saddles for wide chimneys
A chimney more than about 30 inches wide creates a dam on its uphill side, where snow, ice, and debris pile up and water ponds. Building convention and modern code guidance call for a cricket: a small peaked saddle framed behind the chimney that splits the flow and sends it around both sides. We fabricate and flash crickets on chimneys that never had one — common on the older housing stock around Wellesley — and rebuild failed ones. If your leak shows up on the chimney's high side, a missing cricket is a prime suspect.
5Material selection and upgrades
We work in aluminum, galvanized and stainless steel, copper, and lead-coated copper, and we will tell you honestly where each belongs. Aluminum is economical but should not sit against damp mortar for the long haul; copper costs more and can outlive two roofs; stainless shrugs off the coastal salt air that eats galvanized coatings in a decade. On historic homes we match existing copper work rather than mixing metals. The right choice depends on your roof's age, your budget, and your exposure — a coastal cape and an inland colonial do not get the same recommendation.
6Reglet repointing and roof integration
Flashing repair is masonry work as much as metal work. We repoint the joints we cut, match mortar color as closely as the wall allows, and address crumbling joints adjacent to the flashing line while we are up there — there is no sense seating new metal into failing mortar. We also coordinate cleanly with roofers: if your roof is being replaced, we can handle the chimney intersection as part of that project, and if we find shingle or decking problems beyond the flashing, we document them for your roofing contractor rather than pretending they do not exist.
How We Diagnose and Fix It
The single biggest advance in chimney diagnosis is the flue camera. A chimney's interior used to be judged with a flashlight and a mirror from the bottom; today a sweep runs a camera the full height of the flue and sees every tile joint, crack, gap, and deposit in detail. This matters because flue damage is both invisible and consequential — a cracked tile or open mortar joint can expose framing to heat and gases without producing any symptom a homeowner would notice. When we scan a flue at Upside Down Chimney Sweeps, the homeowner can see the footage too, which turns the diagnosis from take-our-word-for-it into something you can evaluate yourself. If a contractor proposes significant interior work without camera evidence, it is entirely fair to ask why.
A well-run repair project follows a predictable arc. It starts with the inspection findings, documented in photos or video you can review yourself. From there, the contractor writes a scope: what will be done, with what materials, in what order, and what it costs — itemized so you can see where the money goes. Scheduling comes next, often shaped by weather, since masonry work has temperature requirements. On work day, expect drop cloths and dust control inside if the job touches the firebox or flue, and staging or roof access outside. Afterward, a reputable outfit walks you through what was done, ideally with after photos taken from the same angles as the before shots. For a project like flashing repair, that documentation trail is not bureaucracy — it is how you verify you got what you paid for.
Warning Signs to Watch For
- Water stains on ceilings or walls adjacent to the chimney, especially after wind-driven rain.
- Visible tar or roofing cement smeared around the chimney's base — evidence of a previous shortcut repair.
- Rust streaks running from the chimney base down across the shingles.
- Lifted, bent, or missing pieces of flashing after a windstorm.
- Visible gaps between the counter-flashing and the mortar joint it should sit in.
- Popped nails or loose fasteners along the flashing line.
- Shingles that look wavy, curled, or spongy in the courses beside the chimney.
- Attic sheathing that is dark, damp, or delaminating around the chimney — especially on its uphill side.
- Leaks that appear during nor'easters but not during gentle vertical rain.
- Moss or algae concentrated right at the roof-to-chimney intersection.
Why This Matters in Wellesley
Wellesley is known for its substantial Tudor, Georgian, and colonial revival homes from the early 20th century, many with two, three, or more fireplaces served by large multi-flue brick chimneys. Ongoing teardown-and-rebuild activity adds new construction with high-end masonry and gas fireplaces. Original clay tile liners in the prewar homes are a common relining project.
Wellesley homeowners tend to invest in doing chimney work properly, and the town's prewar Tudors reward it: ornate chimney tops with decorative brickwork and clay pots require repair techniques that preserve the original look. We match mortar color and brick profile carefully on these projects because the details are visible from the street.
Snow itself sits gently on a chimney, but what snow becomes is another matter. Roof snow melts against warm flashing and refreezes at night, prying the metal away from the masonry one thin layer of ice at a time. Ice dams back meltwater up the roof slope until it finds the flashing seams at the chimney, one of the most common leak paths we trace in Wellesley homes. Meanwhile, snow resting on the crown melts downward into any crack it can find, feeding the freeze-thaw cycle at the chimney's most vulnerable point. If you have ever noticed a water stain near the chimney after a heavy winter, this chain of events is the likely author, and the repair usually starts at the flashing.
What It Typically Costs
An inspection is the least expensive service a chimney company offers and the one that determines everything else, so it is worth understanding what you are paying for. A proper inspection is methodical: firebox, damper, smoke chamber, accessible flue, crown, cap, flashing, and exterior masonry, all documented with photographs. Where conditions warrant, a video scan of the flue interior shows what no flashlight can, including cracked tiles and failed joints deep in the stack. The report you receive should let you make decisions calmly, with evidence, ranked by urgency. Paying for that clarity once a year, as NFPA 211 recommends, is what allows every other chimney dollar you spend to be spent on the right thing.
Why Call Upside Down Chimney Sweeps
One thing homeowners appreciate about Upside Down Chimney Sweeps is that we handle the whole chimney, not just one slice of it. Sweeping, camera inspections, cap and damper replacement, crown repair, flashing, waterproofing, repointing, liner installation, and full rebuilds all live under one roof. That breadth matters because chimney problems rarely respect trade boundaries: a leak may involve the flashing, the crown, and the mortar joints all at once, and a company that only sells one fix tends to see only one cause. Because we diagnose and repair across the entire system, we can recommend the remedy the chimney needs rather than the one we happen to offer. Fewer handoffs also means one point of accountability from first call to final walkthrough.
Frequently Asked Questions
What is chimney flashing, exactly?
What is the difference between step flashing and counter-flashing?
Why not just seal it with roofing tar?
Should I call a roofer or a chimney company for a flashing leak?
Which flashing metal is best, especially near the coast?
What is a cricket, and does my chimney need one?
How long does the repair take, and how long will it last?
My roof is being replaced — should the flashing be redone at the same time?
Get It Handled Today
If your chimney is due, or overdue, for attention, the next step is a short phone call. Reach Upside Down Chimney Sweeps at (781) 653-5644 and we will find a time that works, usually sooner than you might expect for Wellesley addresses given how close we are. Tell us what you have noticed, or simply tell us it has been a while; either one is a fine place to start. One visit gets you a swept flue, a documented inspection, and straight answers about anything we find along the way. Your fireplace should be the most relaxing thing in your house, not a question mark hanging over it. Let us make sure it stays that way.
Serving Wellesley Same-Week
Our Melrose shop is 18 miles from Wellesley. Call (781) 653-5644 for fast scheduling.
Mon–Sat: 7:00 AM – 7:00 PM · Emergency service available
