Whole-system duct and dryer vent check with before-and-after photos - you see exactly what came out of your vents
That "$99 whole-house special" is a bait ad - the real number appears once they are in your hallway, or the "clean" is a shop-vac at the register. We photograph the inside of your ducts before and after instead.
Before
After
Before
After
Before
AfterTrusted Duct Repair & Sealing for Rockville Homeowners
Rockville Duct Repair & Sealing typically costs $350-$1,200 depending on whether you’re sealing accessible joints or replacing collapsed flex runs, and most jobs are completed in a single visit with a written price agreed before any work starts. At CleanRun Air Duct Cleaning Rockville, we’ve documented the inside of every duct run we’ve touched since 2013, and that photo record goes to the homeowner before the truck leaves the driveway.
Rockville’s housing stock tells a specific story. The split-levels and colonial revivals built from the 1960s through the 1980s in neighborhoods like Twinbrook and Lincoln Park still rely on original metal ductwork that’s now pushing 50 years. The newer construction in King Farm and Fallsgrove, built during the 2000s boom, often used flex duct routed through tight attic spaces where summer heat in Montgomery County can degrade the outer jacket. We’ve seen both. We’ve photographed both. And we quote every repair in writing under Haven Standard Clause 1 before a single panel comes off. Call (240) 255-4519 for a free estimate.
Our 365-Day Done Right Promise applies to every duct repair and sealing job we complete in Rockville. If the work isn’t right, we make it right. That’s written on the scope, not just stated in a brochure.
What Our Duct Repair & Sealing Service Includes
Duct Sealing
Duct sealing closes the gaps and separations where conditioned air escapes between the plenum, the main trunk, and the individual duct runs that feed each room. In Rockville, we regularly find 15-30% air loss in homes where the original builder’s tape has dried and curled away from the joints, particularly in attics that hit 140°F in July. We seal with mastic compound and reinforced mesh at every joint, then pressure-test to verify the seal holds. The photo record shows each joint before sealing and the finished work after.
Flex Duct Repair
Flex duct, the insulated flexible tubing common in homes built after 1990, collapses when crushed by storage items in attics or degrades when the outer vapor barrier is damaged by rodents or moisture. In Rockville neighborhoods like Woodley Gardens and College Gardens, we’ve replaced flex runs that were flattened to the point of passing less than 30% of their rated airflow. We cut out the damaged section, install a new length with proper support straps every 4 feet to prevent sagging, and seal the connections with metal-backed tape and mastic. Every repair is photographed and the images are delivered as part of your job record.
Metal Duct Repair
Metal ductwork, the galvanized steel or aluminum found in older Rockville homes, develops rust at seams where condensation collects, or separates at joints due to thermal expansion over decades. We repair rusted sections by cutting out the damaged metal and fabricating a replacement piece, or we seal separations with slip joints and screws followed by mastic. In homes near Rockville Pike where original 1960s construction still stands, we’ve restored metal trunks that were leaking at every branch connection. The work is photographed at each stage.
Duct Insulation
Duct insulation wraps the exterior of metal or flex duct to maintain the temperature of conditioned air as it travels through unconditioned spaces like attics, crawl spaces, or garages. In Rockville’s climate, where January nights drop below 20°F and summer attic temperatures exceed 130°F, uninsulated or degraded insulation forces your HVAC system to reheat or recool the air it’s already conditioned. We install new fiberglass or foil-faced insulation with a proper vapor barrier, sealed at every seam, and we photograph the before condition and the completed installation.
Mastic Sealant
Mastic is a thick, water-based compound that remains flexible after drying, making it the professional standard for sealing duct joints against air leakage. Unlike foil tape, which can fail when surfaces aren’t perfectly clean, mastic fills small gaps and conforms to irregular surfaces. We brush or trowel mastic at every joint, seam, and penetration in your duct system, then reinforce with fiberglass mesh at high-stress points. In Rockville, where humidity swings from 35% in winter to 80% in summer, mastic outperforms tape that can delaminate. The photo record shows the application at each joint.
Air Leak Repair
Air leak repair targets the specific points where your duct system loses conditioned air to unconditioned spaces, identified through visual inspection, pressure testing, or thermal imaging. We commonly find leaks where duct runs pass through wall plates, at disconnected boots behind registers, and at the return air pathway where the filter cabinet meets the furnace. In Rockville’s tighter new construction, even small leaks pressurize wall cavities and drive moisture into building materials. We seal each leak with the appropriate method, pressure-test to confirm, and document the repair with before-and-after photography.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Brands We Service for Duct Repair & Sealing
We regularly work with duct systems connected to Honeywell air cleaners and whole-house humidifiers, particularly in Rockville homes where these accessories are integrated into the return ductwork. Our technicians understand how to remove, service, and reinstall Honeywell components without disturbing the sealed duct connections, and we stock the common gaskets and fittings that fail after years of thermal cycling.
Aprilaire humidifiers and ventilation controllers are common in the higher-efficiency systems we see in King Farm and North Farm. We’ve serviced hundreds of Aprilaire units and carry the OEM replacement parts for their duct-mounted components, including the water panels and distribution trays that integrate directly with your ductwork. Whether you have Aprilaire, Honeywell, or any other make, we can repair and seal the duct connections without voiding your equipment warranties.
Before
AfterSigns You Need Duct Repair & Sealing Right Now
- Rooms that never reach the thermostat setting. If your master bedroom in Rockville stays 8-10 degrees warmer than the hallway in summer, the duct run serving that room is likely crushed, disconnected, or leaking into the attic. You’re paying to cool a space you don’t occupy.
- Dust accumulation around registers despite regular filter changes. When supply ducts leak in unconditioned spaces, they create negative pressure that pulls attic dust, insulation particles, and rodent debris into the system. The camera often shows a gray coating on the duct interior just past the leak point.
- Unusually high summer electric bills with no change in usage. A typical Rockville home loses 20-30% of cooled air to attic leaks. Your HVAC runs longer to compensate, and the compressor draws more power during those extended cycles. We’ve seen bills drop 15-25% after sealing alone.
- Whistling or rushing air sounds from walls or ceilings. These noises indicate high-velocity air escaping through gaps in the ductwork, often at a joint that has separated or a boot that has pulled away from the drywall. The sound is the symptom; the energy waste and pressure imbalance are the problems.
- Musty odors when the system first starts. Leaks in return ductwork draw humid, unconditioned air from crawl spaces or wall cavities where mold grows on organic surfaces. In Rockville’s clay-heavy soils, crawl spaces stay damp year-round, making this a recurring issue in homes with pier foundations.
Our Duct Repair & Sealing Process - Step by Step
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Written estimate before work begins. We inspect your accessible ductwork, identify the specific repairs needed, and deliver a written price under Haven Standard Clause 1. No work starts until you have the number in hand. This is not a “range” or “starting at” figure; it’s the price for the scope described.
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Photographic documentation of every duct run. Before any repair, we photograph the condition of each duct section we’ll be working on. These images become part of your permanent job record, delivered with the final invoice. You’ll see what we saw.
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Targeted repair with trade-verified methods. We seal with mastic and reinforced mesh, replace flex duct with proper support and slope, repair metal with fabricated replacements or slip joints, and insulate with vapor-barrier materials appropriate to Rockville’s climate. We use Nikro negative-pressure extraction equipment to control dust during the work.
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Pressure testing and airflow verification. After repairs, we test the system to confirm sealed joints hold under operating pressure and that airflow at each register meets design specifications. We document the test results in writing.
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Final photo record and written warranty delivery. We photograph the completed work, compile the before-and-after record, and present it with your invoice and the 365-Day Done Right Promise in writing. Haven Standard Clause 4: Documented Completion.
How Much Does Duct Repair & Sealing Cost in Rockville?
A typical duct sealing job in Rockville runs $350-$650 for accessible joints in a single system, while flex duct replacement for 2-3 damaged runs usually falls between $600 and $1,200 depending on attic accessibility and the length of duct involved, so check how much Duct Repair & Sealing costs for your situation. Metal duct repair, which requires fabrication and more labor hours, generally ranges from $800 to $1,500 for rusted sections or separated main trunks. Full duct insulation replacement in an average Rockville attic runs $1,000-$2,400 based on the linear footage and whether we’re working around existing HVAC equipment.
Several factors move the price within these ranges. Attic access is the biggest variable; a walk-up attic with decking allows faster work than a scuttle hole over a hallway with blown insulation to navigate. The number of duct runs affected matters, as does whether we need to coordinate with an HVAC technician for refrigerant line protection during metalwork. Homes in older Rockville neighborhoods like West End and East Rockville sometimes require additional time to work around knob-and-tube wiring or asbestos-containing materials that we identify and flag before disturbing.
To avoid overpaying, get the scope in writing before work starts and verify what’s included. Our estimates specify the number of joints to be sealed, the linear footage of duct to be replaced or insulated, and the materials to be used. We also offer a Free Second Opinion on any written estimate from another company; bring us their scope and we’ll put our number next to it, also in writing.
Every estimate we provide in Rockville is free, includes the full photo documentation of existing conditions, and carries no obligation. Call (240) 255-4519 to schedule.
Duct Repair & Sealing Near Rockville - Our Service Area
We complete duct repair and sealing work throughout Montgomery County and into adjacent Fairfax and Loudoun counties, with regular jobs in Gaithersburg where the 1980s and 1990s subdivisions share Rockville’s flex-duct challenges, and Bethesda where older homes present similar metal duct issues. We also serve Silver Spring, McLean, Reston, Washington, Sterling, Arlington, Herndon, Ashburn, and Fairfax. Most Rockville appointments are scheduled within 3-5 business days, with emergency response available for complete duct collapses or disconnections that have left a home without heating or cooling.
Serving Rockville, MD - Our Local Coverage Area
We’re based in the Rockville area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked Questions - Duct Repair & Sealing in Rockville
Duct repair and sealing fixes the physical damage and air leaks in your home’s hidden network of metal or flexible tubes that carry heated and cooled air from your HVAC equipment to each room. The repair component addresses crushed, rusted, or disconnected sections; sealing closes the gaps at joints and penetrations where conditioned air escapes into attics, crawl spaces, or wall cavities. At CleanRun, every repair and sealing job includes a written scope, a written price agreed before work starts, and a Documented Photo Record of every duct run.
Most duct sealing jobs in Rockville are completed in 3-5 hours, while flex duct replacement or metal duct repair typically takes a full day depending on attic access and the extent of damage. We schedule the work at a specific time, not a window, and the technician calls 30 minutes before arrival under Haven Standard Clause 2: Confirmed Arrival. You’ll know the expected duration before we start, because it’s written on the scope alongside the price.
Duct sealing for accessible joints typically runs $350-$650, flex duct repair or replacement ranges from $600-$1,200, and metal duct repair generally falls between $800-$1,500 in the Rockville market. Full insulation replacement runs higher, from $1,000-$2,400. The exact price depends on your specific system configuration, which we assess during the free estimate visit and document with photographs. Call (240) 255-4519 for an exact quote; estimates are free and include the photo record of existing conditions.
Yes. We regularly repair and seal ductwork connected to Honeywell air cleaners, whole-house humidifiers, and ventilation controls, and we service Aprilaire humidifiers and ventilation systems integrated into duct systems throughout Rockville. Our technicians carry common OEM fittings and understand the clearance and connection requirements for these brands. We also work with Abatement Technologies equipment and any other manufacturer; the duct repair methods are standardized even when the connected equipment varies.
We respond to urgent duct failures, including complete disconnections that leave a home without heating or cooling, collapsed flex duct blocking airflow entirely, or separated main trunks causing system shutdown. All calls are answered by a live person, 24/7, and we prioritize genuine emergencies that affect habitability. For non-urgent repairs, we schedule within 3-5 business days. Call (240) 255-4519 and we’ll assess the situation directly.
Every duct repair and sealing job is backed by our 365-Day Done Right Promise: if the work is not right, we make it right, backed in writing on every scope of work. Haven Standard Clause 5: Accountable Workmanship. This covers the seals, the materials, and the labor. If a sealed joint fails within 365 days, we return and reseal at no charge. The warranty is transferable if you sell the home during that period.
Clear a path to your HVAC equipment and the attic access or crawl space entry; remove stored items that block the work area. We need access to every register in the home for airflow verification after repairs. If you have pets, secure them in a separate room during the work. We bring drop cloths, shoe covers, and our own lighting. You’ll receive the written scope, the written price, and the photo record without any preparation required on your part beyond basic access. Call (240) 255-4519 to schedule; we’ll confirm what’s needed when you book.
Schedule Your Duct Repair & Sealing Service in Rockville Today
Call (240) 255-4519 to speak with a live person and schedule your free estimate. We’ll arrive on time, photograph every duct run before touching anything, deliver a written price under Haven Standard Clause 1, and leave you with a Documented Photo Record and a 365-Day Done Right Promise in writing. No coupons, no per-vent pricing, no surprises. Just documented work you can verify.
Written by Tomas Reyes, Owner at CleanRun Duct Repair & Cleaning, serving Rockville since 2013.