Westwood, MA · Norfolk County

Chimney Flashing Leak Repair in Westwood, 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) 653-5644

Every autumn, searches for "chimney flashing leak repair" 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.

In Massachusetts, a chimney is not seasonal decoration — it is infrastructure. The heating season here runs from October into April, and many chimneys serve double duty, venting a wood-burning fireplace on one flue and an oil or gas heating appliance on another. That means a chimney problem can compromise not just cozy fires but the system that keeps pipes from freezing in January. It also means the flues get real use: months of thermal cycling, condensation, and byproduct accumulation every single year. A problem that might stay dormant for a decade in a milder climate gets stress-tested here every winter. That is the practical reason Massachusetts homeowners cannot treat chimney symptoms casually — the season that reveals the problem is the same season you can least afford to lose the chimney.

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 Westwood, MA

Upside Down Chimney Sweeps rebuilds and repairs chimney flashing across Westwood 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.

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.

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 Westwood — 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.

When a flue can no longer safely contain heat and gases — cracked tiles, open joints, or no liner at all — relining is the fix, and stainless steel is the workhorse solution. The process: the flue is measured and the liner sized to the appliance it serves, because an oversized flue drafts poorly and condenses creosote. The stainless liner is lowered down the chimney, connected to the appliance or fireplace below, insulated in most cases to improve draft and meet listing requirements, and finished with a top plate and cap. Done properly, it creates a continuous, sealed, correctly sized passage from appliance to sky. Relining sounds invasive but usually takes about a day, involves no demolition in most homes, and is frequently the single most consequential safety upgrade an older Massachusetts chimney can receive.

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 Westwood

Westwood's Islington section carries compact prewar and postwar homes on smaller lots, while the rest of town features mid-century colonials and a strong wave of recent teardown rebuilds with high-end finishes. Older homes typically have a single brick fireplace chimney, and the new construction trends toward gas fireplaces with direct vents alongside traditional masonry.

Westwood's steady teardown-and-rebuild market means we see both ends of the spectrum in one town: 70-year-old chimneys that need honest assessment before a sale, and brand-new masonry where builders cut corners on crowns or flashing. Pre-purchase Level 2 inspections are a big part of our work here.

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 Westwood 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

Relining a flue is among the larger chimney investments, and its cost logic is worth demystifying. Price follows the liner's length and diameter, the material chosen, whether the new liner needs insulation to meet the requirements of the appliance it serves, and how much work is required to remove or bypass the old damaged tiles. What the chimney vents matters too: a liner for a wood stove faces different demands than one venting a gas furnace, and sizing it correctly affects both safety and draft performance. Because so many variables interact, legitimate liner quotes follow a camera inspection rather than a phone call. When we propose a liner, we show you the footage that justifies it.

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?

Flashing is the layered sheet-metal system that waterproofs the joint where your chimney passes through the roof. Because the roof structure and the masonry move independently, no rigid or glued seal can survive there. Instead, flashing sheds water by overlapping: step flashing woven into the shingle courses carries water down the roof plane, and counter-flashing embedded in the chimney's mortar joints covers the tops of those steps so water running down the brick is thrown clear. Add an apron on the downhill face and a back pan or cricket uphill, and every side of the chimney has a gravity-fed drainage path. No adhesive is doing the real work — the geometry is.

What is the difference between step flashing and counter-flashing?

They are two layers with two jobs. Step flashing belongs to the roof: individual L-shaped pieces, one per shingle course, each tucked under a shingle and lapped over the piece below, fastened to the roof deck. It handles water flowing down the roof plane. Counter-flashing belongs to the chimney: pieces set into grooves cut in the mortar joints, bent down over the step flashing's vertical legs. It handles water flowing down the masonry face. The critical detail is that the two layers overlap without being attached to each other, so the roof and the chimney can move independently through the seasons without tearing the seal open.

Why not just seal it with roofing tar?

Roofing cement is a bandage, and everyone in this trade knows it. It bonds poorly to dusty masonry, turns brittle in the cold, shrinks away from edges within a couple of seasons, and — the part homeowners rarely hear — it can trap water behind it, holding moisture against the mortar through freeze-thaw cycles and accelerating the very damage it was hiding. It also buries the evidence, so the next diagnosis takes longer and costs more. We remove tar patches; we do not add to them. A proper counter-stepped metal system costs more on the day it is installed and dramatically less over the life of your roof.

Should I call a roofer or a chimney company for a flashing leak?

It is genuinely a boundary trade, which is why homeowners get bounced between the two. Roofers are excellent on the shingle side but often surface-mount counter-flashing with caulk rather than cutting it into the mortar, because masonry is not their trade. A chimney company that does masonry can cut reglets, repoint, and judge whether the leak is actually the crown or the brick rather than the flashing at all. We handle the full intersection and coordinate with your roofer when the job crosses into the roof field. Whoever you hire, ask one question: will the counter-flashing be let into the mortar joint? If the answer involves caulk, keep calling.

Which flashing metal is best, especially near the coast?

For most inland Greater Boston homes, aluminum or galvanized steel is serviceable and economical, but both have limits: aluminum reacts with damp mortar over time, and galvanized coatings fail early in salt air. Within a few miles of the ocean we push toward stainless steel or copper — coastal exposure corrodes cheap metal astonishingly fast, and we regularly replace galvanized flashing barely fifteen years old in shoreline towns. Copper is the premium choice everywhere: it forms beautifully, ages to a quiet brown, and routinely outlasts two shingle roofs. On historic homes in and around Westwood, matching existing copper work is usually the right call both structurally and visually.

What is a cricket, and does my chimney need one?

A cricket, or saddle, is a small peaked structure built on the uphill side of a chimney to split water and snow around it instead of letting the chimney act as a dam. Modern building practice calls for one when the chimney is wider than about 30 inches across the slope. Without a cricket, the high side collects leaves, snowpack, and ponded water, and that standing load eventually beats any flat back pan. Many chimneys on older Massachusetts homes were built without one, which is why chronic high-side leaks are so common here. If your stains are on the uphill side of the chimney, ask us to check for this first.

How long does the repair take, and how long will it last?

Most full flashing rebuilds are a one-day job; targeted repairs of a single failed section often take a few hours. Weather matters — we want dry shingles, workable temperatures for sealants and mortar, and safe footing, so winter scheduling can shift with the forecast. As for longevity: properly counter-stepped metal set into sound mortar should last as long as the roof itself, and copper considerably longer. The honest caveat is the surrounding masonry — flashing set into crumbling joints will never reach its potential, which is why we repoint the reglet line as part of the job rather than treating it as an upsell.

My roof is being replaced — should the flashing be redone at the same time?

Yes, almost always, and the timing is a gift: with the shingles off, the entire intersection is exposed, membrane can be run properly, and new step flashing costs the least it ever will. Reusing old step flashing under a new roof is a common corner-cut we would talk you out of — thirty-year shingles deserve better than twenty-year-old metal. Coordinate the sequence: we can cut reglets and set counter-flashing right after the roofer finishes the field, or handle the full chimney intersection ourselves as part of the project. Call (781) 653-5644 before the roofing crew starts and we will slot the chimney work into their schedule.

Get It Handled Today

You searched for chimney flashing leak repair, and the search can end here. Upside Down Chimney Sweeps handles this work for Westwood homeowners regularly, following NFPA 211 standards, documenting everything with photographs, and explaining findings without jargon or pressure. Call (781) 653-5644 to talk through your situation with someone who does this every day; a few minutes on the phone is usually enough to scope the visit and set a time. We show up when promised, protect your home while we work, and stand behind the results. There are certainly bigger companies and flashier websites out there, but for careful chimney work done close to home, we like our chances of earning your call and then keeping your business.

Serving Westwood Same-Week

Our Melrose shop is 19 miles from Westwood. Call (781) 653-5644 for fast scheduling.

Call (781) 653-5644 Email Us

Mon–Sat: 7:00 AM – 7:00 PM · Emergency service available