Everett, MA · Middlesex County
Chimney Waterproofing & Sealing in Everett, MA
Brick and mortar drink water like a sponge — then New England winter freezes it. Our breathable siloxane treatments stop the absorption before spalling starts.
Most chimney waterproofing treatments in the Boston area run $300–$750 depending on chimney size and roof access, with crown coating or minor repointing adding a few hundred more when needed.

Maybe you noticed a damp smell from the fireplace after last week's rain. Maybe smoke curled into the living room instead of up the flue, or a chunk of mortar appeared in the firebox, or a neighbor's chimney fire got you thinking. Homeowners in Everett usually call us because something small felt slightly off, and that instinct is worth trusting. Chimneys telegraph their problems in modest ways long before those problems become expensive ones. Upside Down Chimney Sweeps can tell you quickly whether what you noticed is a harmless quirk or an early warning. One inspection, a set of photographs, and a plain-English conversation will replace vague worry with a concrete plan, whatever that plan turns out to be.
Set a dry brick in an inch of water and come back in an hour: the waterline will have climbed the brick like a wick. Masonry is a sponge — brick, mortar, and block all pull water inward through capillary action, and the portion of your chimney above the roofline gets wetted on all four faces by every storm that crosses Massachusetts. In summer, most of that moisture evaporates back out. From November through April it does something worse: it freezes in place, expands roughly nine percent, and pries the masonry apart from within — flaking brick faces, powdering mortar, and opening ever-larger pathways for the next storm to exploit. Chimney waterproofing exists to interrupt that cycle at its first step, by stopping the absorption itself.
The word waterproofing suggests paint or a rubber coating, and that is exactly what it must not be. Masonry constantly needs to release vapor — moisture from combustion, from condensation inside the flue, and from the house itself migrates outward through the brick. A film-forming sealer traps that vapor behind an impermeable skin, where winter freezes it and shears the brick face right off; chimneys sealed with the wrong product often spall faster than untreated ones. What we apply instead is a penetrating siloxane- and silane-based water repellent: it soaks into the pore structure and chemically lines the pores so liquid water cannot wick in, while water vapor still passes out freely. The chimney sheds rain like waxed canvas but continues to breathe.
Waterproofing is the finishing move of good chimney maintenance, never a substitute for repair. A repellent cannot bridge a cracked crown, fill an open mortar joint, or re-seat failed flashing — water pouring through a defect simply bypasses the treatment. So we sequence the work properly: repoint failing joints, repair or coat the crown, confirm the cap and flashing are sound, and only then flood-coat the masonry field. Applied to a sound chimney, a quality repellent keeps the brick dramatically drier through the freeze-thaw season, slows spalling to a crawl, starves efflorescence and moss of the moisture they feed on, and typically protects for eight to ten years before re-treatment is due.
Chimneys around Everett earn this protection more than most. Eastern Massachusetts stacks the deck against masonry: nor'easters that drive rain horizontally for hours, dozens of freeze-thaw cycles in a single winter, and — closer to the shore — salt air that keeps surfaces damp and accelerates decay. Much of the region's housing stock predates modern water-management details entirely, and older chimneys that once ran hot and dry over coal or wood fires now vent cooler, wetter appliance exhaust that adds moisture from the inside. Upside Down Chimney Sweeps applies breathable water repellents across Greater Boston from our shop in Melrose; call (781) 653-5644 and we will tell you honestly whether your chimney is a candidate or needs repair work first.
What Our Waterproofing Service Covers
1Pre-treatment condition assessment
We never spray a chimney we have not inspected. Before quoting waterproofing we examine the crown for cracks, the cap and flashing for function, the mortar joints for depth and hardness, and the brick faces for spalling — photographing all of it. If the masonry needs repair, we tell you and price it, because repellent applied over defects is money wasted. We also look for signs of internal moisture, like efflorescence patterns that suggest flue condensation, which waterproofing alone cannot solve. The assessment protects you from paying for the wrong fix.
2Vapor-permeable repellent application
We apply professional-grade siloxane and silane water repellents formulated for chimney masonry — never film-forming acrylic sealers. The material goes on as a flood coat, saturated from the bottom of the stack upward so the run-down soaks in evenly, followed by a second wet-on-wet pass that drives penetration deeper into the pore structure. Proper coverage rates matter more than brand names; a light misting fails early. Treated masonry beads and sheds rain while remaining fully breathable, and because the chemistry bonds inside the pores, it will not peel, blister, or discolor with UV exposure.
3Crown sealing and elastomeric coating
The crown — the sloped top surface that sheds water off the stack — takes more direct water than any brick below it, and hairline crown cracking is nearly universal on chimneys more than a decade old. As part of a waterproofing package we clean the crown, fill hairline cracks, and apply a flexible elastomeric crown coating that bridges movement through seasonal thermal cycling. Crowns that are structurally failed rather than surface-cracked get flagged for proper repair or rebuild instead — coating a collapsing crown just hides the problem for a season or two.
4Repointing and spall preparation
Repellent needs sound masonry to protect. Where we find scattered failing joints or a few spalled faces, we cut out and repoint the bad joints with compatible mortar and replace individual damaged bricks before treatment, giving new mortar time to cure before the flood coat goes on. Matching mortar hardness matters on the older homes around Everett — a hard modern high-Portland mix against soft historic brick transfers stress into the brick itself. Small repairs folded into the same project keep the chimney watertight as a system rather than sealing defects permanently in place.
5Efflorescence and stain removal
Those white, chalky blooms on brick are efflorescence — mineral salts carried to the surface by migrating water and left behind as it evaporates. Beyond looking bad, they are a map of your chimney's moisture problem. We clean efflorescence, algae, and organic staining with appropriate masonry cleaners and low-pressure rinsing — never aggressive blasting, which opens the brick's pores further. A repellent applied over heavy salt deposits bonds poorly; cleaned first, it penetrates properly. And because treated brick stays drier afterward, the staining largely stops coming back.
6The full water-management check
Waterproofing only earns its keep as part of a complete water-management system, so every job includes a check of the other components: cap present and correctly sized, chase covers free of ponding, flashing engaged in its mortar joints, and the flue itself free of the condensation clues that point toward a liner problem. Where something is wrong we document it with photos and price the fix separately — no bundling games. The goal is simple: every path water can take into your chimney is either shed, sealed, or flagged, and you know exactly where things stand.
Why Waterproofing Matters for Everett Homes
The arithmetic of waterproofing is lopsided. Treatment costs a few hundred dollars and lasts the better part of a decade; the failures it prevents — spalled brick faces, deep repointing, crown rebuilds, and in the worst cases partial chimney rebuilds — run from the low thousands into five figures. Freeze-thaw damage is also self-accelerating: every popped brick face and opened joint admits more water, so deterioration that took decades to begin can finish a chimney within a few hard winters around Everett. Buying back that timeline for the price of a service call is the best value in chimney work, full stop.
Chimneys are unusual among masonry structures because they get wet from both directions. Rain attacks from outside while combustion vapor — especially from modern gas and oil appliances pushing cool, moist exhaust up old flues — condenses on the inside. This is why breathability is not a nice-to-have: a chimney sealed under an impermeable film has nowhere to release its internal moisture, and winter turns that trapped water into a wrecking bar working from within. Vapor-permeable repellents solve the outside problem without creating an inside one, and guidance from the Chimney Safety Institute of America (CSIA) likewise favors breathable repellents over paint-on sealers for exactly this reason.
No repellent rescues a chimney with a broken crown, failed flashing, or an uncapped flue — the biggest water entries are openings, not absorption. That is why we inspect before we treat and repair before we seal, and why we recommend keeping the annual inspection habit that NFPA 211 prescribes for every chimney, whether it is used regularly or not. An annual look catches the small stuff — a new hairline in the crown coat, a joint starting to soften — while it still costs almost nothing to fix, and confirms your waterproofing is still beading water years into its service life. Protection is a practice, not a product.
Nor'easters give chimneys in Everett a beating that ordinary storms never match. These coastal systems drive rain and snow horizontally for hours at a time, forcing water against the sides of a chimney rather than politely down onto its cap. Wind-driven rain exploits every weakness: hairline cracks in the crown, thin spots in mortar joints, and lifted flashing at the roofline all become entry points under that kind of pressure. Homeowners often discover the aftermath weeks later, as a ceiling stain near the chimney or a damp, smoky odor in the firebox. After a hard nor'easter season, a careful inspection of the crown, flashing, and masonry is not paranoia; it is how storm damage gets caught while the fix is still small.
Signs You Need Waterproofing in Everett
- Brick that darkens in the rain and stays dark for hours after the storm has passed.
- White, chalky efflorescence blooming on the chimney's exterior faces.
- Small flakes or popped faces of brick appearing on the roof or on the ground below.
- Mortar joints that feel sandy or crumble when touched.
- Hairline cracks spidering across the chimney crown.
- Musty fireplace odors that come and go with humid weather.
- Interior staining near the chimney that appears seasonally rather than after specific storms.
- Moss, lichen, or algae colonizing the shaded faces of the masonry.
- Frost blooming on the exterior brick during winter cold snaps.
- A chimney that has never been treated, or was last waterproofed more than eight to ten years ago.
How the Job Goes, Step by Step
1Inspection and candidacy check
We start by confirming waterproofing is actually the right move. A technician inspects the crown, cap, flashing, joints, and brick faces, checks moisture behavior, and photographs the stack top to bottom. Chimneys with active defects get a repair plan first; chimneys already sound get scheduled for treatment. Either way you receive an honest written assessment — we would rather lose a waterproofing sale than seal a chimney that needed repointing.
2Repairs first, with curing time
Any needed repairs happen before treatment: repointing, spalled brick replacement, crown crack fill or elastomeric coating. Fresh mortar then needs time to cure before repellent is applied, so on chimneys needing masonry work we schedule the treatment as a short follow-up visit. Sequencing this correctly is the difference between a repellent that performs for a decade and one that locks moisture into green mortar.
3Cleaning and surface prep
The masonry is cleaned of efflorescence, soot streaking, moss, and organic growth using masonry-appropriate cleaners and gentle rinsing. The surface must be sound, clean, and dry for the repellent to penetrate — application over dirt or salt deposits is the most common cause of early failure. We also verify a dry-weather window, since the brick needs to be dry going in and rain-free for several hours afterward.
4Masking and protection
Before spraying, we protect everything the repellent should not touch: surrounding roofing is covered, adjacent siding shielded, and plantings below the work area draped. Overspray control is part of the craftsmanship — siloxane repellents are not something you want beading on your shingles or windows. Ladders and staging are set so the entire stack, including the tight faces near the roofline, gets even coverage rather than just the easy sides.
5Two-pass flood application
We apply the repellent as a saturating flood coat from the bottom of the masonry upward, so material running down is absorbed by brick that is already wetting out. A second pass follows wet-on-wet to push penetration deeper. Manufacturer coverage rates are followed, not stretched to save product. The crown coating, when part of the job, is completed in the same visit, and all treated surfaces are left to cure undisturbed.
6Verification and service record
Once cured, treated masonry visibly beads water, and we confirm performance with a light spray test. You receive photos, the name of the product applied, coverage details, and a recommended re-treatment window — typically eight to ten years depending on exposure. We log all of it, so future annual inspections can track how the treatment is holding and catch the right moment to renew it, long before the brick starts drinking again.
Local Knowledge: Waterproofing in Everett
Everett is one of the densest cities in the Commonwealth, built out almost entirely by the 1930s with triple-deckers, two-families, and closely spaced wood-frame singles. Most of these buildings carry original brick chimneys serving stacked heating appliances, and many flues have been switched from coal to oil to gas without ever being properly relined. Flat and low-pitch roofs are common, and access between buildings is tight.
Just four miles from our Melrose shop, Everett is home turf. The chimney story here is urban: aging multifamily stacks, gas-conversion liner work, and tall brick chimneys that loom over three stories of tenants who all depend on the same flue. Landlords and condo associations make up a big share of the calls in this city.
We regularly handle waterproofing calls in Everett and the surrounding towns of Malden, Chelsea, Medford, Revere — so scheduling is fast and our pricing reflects local conditions, not guesswork.
Winter is the season your chimney works hardest, and it deserves some attention even in mid-use. If you burn frequently, deposits accumulate faster than an annual schedule assumes, particularly when the wood is less than fully seasoned; heavy burners sometimes need a mid-season sweep. Winter is also when problems announce themselves: sluggish draft on cold starts, smoke odors migrating through the house, or a damper that suddenly stiffens. None of those should be ignored until spring. And if you ever suspect a chimney fire, however brief, stop using the fireplace and have the flue inspected before lighting the next one. We work straight through the winter for exactly these situations, and prompt attention keeps small issues small.
Why Choose Upside Down Chimney Sweeps
Good chimney work starts with good communication, and we structure every job around it. Before we begin, you get a clear scope and a clear price. During the visit, our technician explains what they are finding and photographs anything noteworthy inside the flue or up on the roof, places you would never see otherwise. Afterward, you receive a report that plainly states the condition of your chimney and any recommendations, ranked by urgency. Call our office and a person who knows your job answers, not a call center reading a script. None of this is revolutionary; it is simply how service companies used to operate, and we think Greater Boston homeowners deserve contractors who still work that way.
Waterproofing FAQs — Everett, MA
What is the difference between waterproofing and just painting or sealing the brick?
How long does chimney waterproofing last?
Can you waterproof a chimney in cold weather?
Will waterproofing change how my chimney looks?
My chimney already leaks — will waterproofing fix it?
Is it worth waterproofing a chimney I barely use, like a gas or oil flue?
What does chimney waterproofing cost?
What actually makes brick spall, and does waterproofing prevent it?
Book Waterproofing in Everett
Chimney calendars around Everett fill fastest exactly when you most want an appointment, so the best time to call is before the season demands it. Whether that means a sweep before the first fire, a repair while the weather still favors masonry work, or an inspection simply because it has been more than a year, Upside Down Chimney Sweeps can get you scheduled with one call to (781) 653-5644. We will confirm the scope, give you an honest price, and show up when we said we would. The homeowners who never seem to have chimney emergencies are, almost without exception, the ones who made this call a little earlier than they strictly needed to.
Book Waterproofing in Everett
Our Melrose shop is 4 miles away — scheduling in Everett is fast. Call (781) 653-5644.
Mon–Sat: 7:00 AM – 7:00 PM · Emergency service available
