Fast, Reliable Duct Repair & Sealing Across Evanston
Duct repair and sealing in Evanston typically costs $280-$650 for most residential jobs, with same-day service available throughout the city. Our crew reaches Evanston homes from our Chicago location, usually within 45 minutes to an hour depending on traffic along Sheridan Road or the Edens Expressway. We’ve been driving these streets since 2012, and we know the difference between a 1920s Craftsman near Dempster Street and a mid-century split-level off Green Bay Road. That matters because the ducts inside are nothing alike. Call (877) 502-3903 for a free estimate - we’ll give you an honest price before we lift a single tool.
Why Bellows Air Duct & Vent Co. of Chicago Is Evanston’s Preferred Duct Repair & Sealing Company
We’ve worked in Evanston long enough to recognize the telltale signs of a gravity-furnace retrofit the moment we step into a basement. Homeowners here don’t need a lecture on their home’s history - they need someone who won’t damage what can’t be replaced. Our Duct Repair & Sealing team has handled jobs from the lakefront mansions of 60201 to the greystone two-flats near Main Street, and our reviews from Evanston customers consistently mention the same thing: we show up when we say, we explain what we’re doing, and we leave the place cleaner than we found it.
Calls to our office are answered by a live person, 24 hours a day. Not a voicemail tree. Not an app. A real person who can dispatch a background-checked, uniformed technician to your Evanston home, usually the same day you call. Most jobs are completed in a single visit. And every one of them is backed by our 90-Day Done Right Promise - in writing, no arguing, no paperwork required if something needs adjustment.
Our Duct Repair & Sealing Services in Evanston
Duct Sealing with Mastic Sealant
Mastic sealant is our go-to for Evanston’s older metal duct systems. The oversized rectangular trunk ducts left behind from gravity-furnace conversions - common west of Sheridan Road in the 60201 ZIP - develop gaps at seams and joints over decades of thermal expansion. Mastic, a water-based paste that cures into a flexible, permanent seal, conforms to irregular surfaces that tape can’t grip. A typical mastic sealing job for a single-family Evanston home runs $320-$480. We apply it by hand, brush it into every seam, and verify the seal with a camera inspection before we leave. No shortcuts around original plaster or lath that might be hiding nearby.
Metal Duct Repair
Galvanized steel trunk ducts in Evanston’s pre-1940 housing stock don’t fail all at once. They rust through at low points where decades of condensation collect, or they separate at joints where original fasteners have corroded. We’ve patched sections near Central Street, replaced collapsed elbows in basements off Dodge Avenue, and reinforced sagging plenums that were one season away from dumping conditioned air into a crawl space. Metal duct repair in Evanston generally ranges from $280 for a localized patch to $620 for section replacement with custom-fabricated galvanized fittings. We fabricate what we can on-site to avoid waiting on parts.
Flex Duct Repair
Flex duct, the insulated plastic tubing common in additions and retrofits, degrades faster in Evanston’s humid lakefront environment than in drier inland suburbs. The plastic liner becomes brittle, the insulation compacts, and the wire helix corrodes. We see this especially in 1960s-1980s additions where flex was run through unconditioned attics. Repair involves replacing the damaged section with new flex, properly supported and sealed to the existing metal trunk. Typical flex duct repair in Evanston: $240-$380 per run. We’ll tell you if the whole run needs replacement or if a localized repair will hold.
Duct Insulation
Uninsulated or degraded duct insulation is a hidden problem in Evanston’s older homes. The original asbestos-containing insulation on many pre-1970 systems has been removed or has crumbled, leaving bare metal ducts that sweat in summer and bleed heat in winter. Lake Michigan moisture makes this worse - humid basement air hits cold duct surfaces, and you’ve got condensation dripping onto your floor joists. We install new fiberglass duct insulation with a vapor barrier, properly sealed at seams. Duct insulation jobs in Evanston typically run $450-$780 depending on linear footage and accessibility. On a recent job near Dempster Street, we re-insulated a full basement trunk system after sealing it with mastic, cutting the homeowner’s summer humidity readings by nearly 15 percent.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Evanston
We carry professional-grade equipment and materials from Rotobrush, Nikro, Honeywell, and Aprilaire - the same brands serious HVAC contractors specify for their own jobs. For Evanston homeowners, this means we don’t need to special-order basic fittings or sealants. Our trucks stock galvanized duct, mastic, fiberglass insulation, and flex duct in standard diameters, so most repairs start and finish without a parts run. When we encounter something unusual - a custom fitting for a historic register, say - we fabricate it on-site or source it from our Chicago warehouse, not from a big-box store.
Common Duct Repair & Sealing Problems We See in Evanston Homes
- Coal soot disturbance without containment. Original gravity-furnace ducts in Evanston’s 1890-1930 housing stock carry a fine black layer of pre-1960s coal soot. If disturbed without proper containment, this residue blows back into living spaces, staining walls and triggering respiratory issues. We document the soot layer with camera inspection before any aggressive cleaning begins.
- Sealing over biological growth. Persistent Lake Michigan moisture elevates humidity in older, loosely sealed Evanston homes, promoting mold and mildew inside duct systems. Sealing leaks without addressing underlying biological growth traps moisture and odors inside, making the problem worse within months.
- Flex-hose equipment on legacy ducts. Standard flex-hose cleaning and sealing equipment is designed for modern round ductwork. Forced onto Evanston’s irregularly shaped rectangular trunk ducts, it leaves gaps at corners and incomplete seals that continue leaking conditioned air.
- Ignoring oversized plenum design. Gravity-furnace plenums were sized for natural convection, not forced air. When homeowners add a modern blower without resizing or sealing these enormous chambers, airflow becomes turbulent and inefficient, straining the equipment and unevenly heating rooms.
Pricing for Duct Repair & Sealing in Evanston, IL
| Service | Typical Range in Evanston |
|---|---|
| Mastic sealant application (seams/joints) | $320-$480 |
| Metal duct repair (patch to section replacement) | $280-$620 |
| Flex duct repair/replacement (per run) | $240-$380 |
| Duct insulation (basement trunk system) | $450-$780 |
| Full system assessment with camera inspection | $89-$150 (credited toward repair) |
What moves a job toward the higher end: accessibility issues (buried drop ceilings, tight crawl spaces), extent of corrosion or biological growth, and whether custom fabrication is needed for non-standard fittings. What keeps it lower: straightforward access, localized damage, and systems that have been maintained. We disclose the full price before work begins - the number on the phone is the number on the invoice. Our $89 Seasonal Tune-Up includes a camera inspection that we credit toward any repair over $250. Seniors and veterans receive a permanent 5% discount. Call (877) 502-3903 for an exact quote - estimates are free.
We Also Serve Cities Near Evanston
Our technicians regularly work in Evanston and the surrounding communities - Wilmette to the north, Skokie to the west, and the Chicago neighborhoods of West Ridge and Rogers Park to the south. The same lake-moisture issues that affect Evanston duct systems appear in these areas too, though often less severely as you move inland. If you’re unsure whether your home falls in our service area, call and we’ll confirm.
Serving Evanston, IL - Our Local Coverage Area
We’re based in the Evanston area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - Duct Repair & Sealing in Evanston
No - we can usually work through removable ceiling tiles or small access panels without disturbing the full installation. On a Craftsman home near Dempster Street, our crew encountered a massive original gravity-furnace plenum in the basement ceiling, buried under a drop ceiling and still coated in fine black coal soot. We used Rotobrush equipment to seal leaks with mastic and re-insulate the duct, carefully documenting the soot layer for the homeowner before any cleaning began. If your ceiling is permanently finished, we’ll discuss minimal-access options during your free estimate. Call (877) 502-3903 to schedule.
We contain and document it before disturbing anything. Our camera inspection records the extent and location of pre-1960s coal soot residue, common in Evanston’s gravity-furnace retrofits west of Sheridan Road. We then seal the work area, use negative air pressure to prevent migration, and remove soot with HEPA-contained equipment rather than blowing it loose. The documentation protects historic-preservation-conscious homeowners and gives us a baseline for post-work verification. Call (877) 502-3903 for an exact quote - estimates are free.
Yes - in most cases, original galvanized trunk ducts from the 1910s-1930s can be sealed and returned to service if the metal is structurally sound. We test for thin spots and corrosion, then apply mastic sealant to all seams and joints, reinforce weak sections with metal patches, and add insulation where the original has degraded. Full replacement is only necessary when the metal has rusted through extensively or when the duct geometry is so oversized that modern equipment cannot achieve proper airflow. A typical seal-and-reinforce job for a 1910 Evanston home runs $380-$580. Call (877) 502-3903 for an exact quote - estimates are free.
It helps, but it’s not a complete solution on its own. Sealing leaks prevents humid basement air from being drawn into the return duct system, which reduces the moisture load your air conditioner must handle. However, persistent Lake Michigan onshore moisture - especially in spring and fall - also enters through the building envelope itself. For Evanston’s older, loosely sealed homes, we often recommend pairing duct sealing with improved basement air sealing and, in some cases, a dedicated dehumidification strategy. After sealing and re-insulating a trunk system near Dempster Street, we measured a 15 percent drop in basement relative humidity. Call (877) 502-3903 to discuss your specific situation.
Minor repairs - sealing, patching, insulating existing ducts - generally do not require a permit in Evanston. Work that modifies the heating or cooling source, changes duct routing, or involves structural modifications may trigger permit requirements through the City of Evanston’s Building & Inspection Services division. We handle permit research as part of our upfront assessment and will tell you before work begins if one is needed. Our 90-Day Done Right Promise covers all work regardless of permit status. Call (877) 502-3903 for an exact quote - estimates are free.
Ready to stop losing heated and cooled air through gaps you can’t see? Bellows Air Duct & Vent Co. has served Evanston and the North Shore for over 42 years. We answer calls with a live person, 24 hours a day. We show up when we say. And we stand behind our work - no paperwork, no arguing - for 90 days in writing. Call (877) 502-3903 today for your free estimate.
Written by Ray Dempsey, Owner at Bellows Air Duct & Vent Co., serving Evanston since 2012.