Burlington, MA · Middlesex County
Roof Flashing Chimney Repair in Burlington, 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) 653-5644New England winters are a stress test that most building materials eventually fail, and chimneys take the worst of it. They stand above the roofline, unprotected, through nor'easters, ice storms, and dozens of freeze-thaw cycles a season — all while channeling combustion gases hot enough to matter. So when a homeowner searches for "roof flashing chimney repair" in Massachusetts, the weather is almost always part of the story. In this guide, Upside Down Chimney Sweeps explains how winter exposure creates or accelerates the problem behind your search, what a thorough diagnosis covers, and why certain repairs last here while others fail within a few seasons. We will also cover timing, because in this climate, when you do the work matters nearly as much as how. Talk to a sweep directly at (781) 653-5644.
Ask any experienced sweep to name the real enemy of chimneys and the answer will not be fire — it will be water. Masonry is porous. Rain and snowmelt soak into brick and mortar, and every time temperatures cross freezing, that trapped water expands roughly nine percent, prying material apart from the inside. In a Massachusetts winter, a single week can deliver several freeze-thaw cycles. The chimney's defenses against this — the crown on top, the cap over the flue, the flashing where brick meets roof, and breathable water repellents on the masonry face — all wear out on their own schedules. When any one fails, water gets in, and nearly every expensive chimney problem we see traces back to that moment. Whatever symptom brought you here, water is the first suspect worth ruling out.
Chimney problems compound in a way most home repairs do not. A roof leak generally stays a roof leak; a chimney defect recruits new ones. A cracked crown admits water, which spalls the top courses of brick, which opens mortar joints, which lets more water reach the flue tiles, which crack in turn — and suddenly a repair that once involved a trowel involves scaffolding. This cascade is the single best argument for acting early. In our experience around Greater Boston, the gap between catching a problem this season versus three seasons from now is frequently the difference between a minor line item and a partial rebuild. You do not need to panic over the issue that prompted your search, but you should resist the very human urge to file it under later.
Chimney Flashing Repair in Burlington, 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.
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.
Two parts of your house meet at the chimney's base, and they refuse to move together. The roof deck expands, contracts, and flexes with every temperature swing and snow load; the masonry chimney, anchored to its own foundation, barely moves at all. Any rigid seal between them is doomed from the day it is installed. That is the entire reason chimney flashing exists: instead of gluing the two structures together, a properly built flashing system overlaps layers of bent metal so water is shed by gravity while each layer stays free to move. Built right, it outlasts the shingles around it. Built wrong — or smeared over with tar — it becomes the single most common source of chimney leaks we see across Burlington.
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 Burlington — 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
Here is what an actual diagnostic visit looks like, so you know what to expect. The sweep starts with questions — when the symptom appears, what changed recently, how you use the fireplace — because the history narrows the possibilities before a ladder comes off the truck. Then the physical inspection: firebox, damper, and smoke chamber from below; crown, cap, flashing, and masonry from the roof; a camera scan of the flue if the situation calls for one. Photos get taken throughout. At the end, you should receive a plain-language explanation of what was found, evidence you can see yourself, and a written scope if work is recommended. The whole process typically fits inside an hour or two. What you should not get is a verdict delivered from the driveway without anyone touching the chimney.
Professional creosote removal is matched to what the inspection found. Stage 1 and Stage 2 deposits come out with rotary or manual brushing sized to the flue, with the firebox sealed off and a HEPA vacuum controlling dust — a properly done sweep leaves no mess in the house. Stage 3 glaze is a different job: hardened, tarry creosote bonds to the flue and must be treated with specialized chemical modifiers that break it down over one or more applications before mechanical removal, and badly glazed flues sometimes force the relining conversation instead. After cleaning, the sweep verifies the flue with a light or camera pass. Equally important is the debrief: what the deposits indicated about wood quality, burn habits, and draft, so the conditions that built the creosote do not simply rebuild it.
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 Burlington
Burlington transformed from farm town to suburb almost entirely after World War II, so its streets are lined with 1950s-1970s capes, ranches, and splits, most built with a single central brick chimney and fireplace. Teardown-and-rebuild activity in recent years has added newer colonials with gas fireplaces. The original mid-century chimneys are now uniformly at the age where crowns, caps, and mortar joints need attention.
Because nearly all of Burlington was built within the same few decades, its chimneys are aging on the same schedule, and whole neighborhoods hit the repointing and crown-repair stage together. Home turnover driven by the Route 128 job market also means a steady flow of pre-sale inspections that uncover decades of deferred maintenance.
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 Burlington 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
The most important thing to understand about chimney costs is how they escalate. A cracked crown is a modest repair. Left alone, that crack admits water; a few winters of freeze-thaw cycling spread the damage into the upper courses of brick, and the modest repair becomes partial rebuilding. Wait longer, and the deterioration reaches the flue tiles and the liner, and now the project involves the chimney's core rather than its surface. Nearly every expensive chimney job we see was once an inexpensive one that waited. This is not a scare tactic; it is the ordinary physics of water and masonry. The cheapest chimney maintenance strategy ever devised is fixing small things while they are still small.
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
A well-maintained chimney is one of those quiet protections a house provides its family, like a sound roof or a dry basement, invisible right up until the moment it matters. Giving your Burlington home that protection takes remarkably little: an annual inspection, sweeping whenever the flue needs it, and small repairs made before winter can enlarge them. Upside Down Chimney Sweeps would be honored to be the company you trust with that work, and starting is as simple as calling (781) 653-5644. We will treat your home with care, your questions with patience, and your budget with respect. The fires will feel better once you know for certain what condition their chimney is really in.
Serving Burlington Same-Week
Our Melrose shop is 10 miles from Burlington. Call (781) 653-5644 for fast scheduling.
Mon–Sat: 7:00 AM – 7:00 PM · Emergency service available
