Duct Sealing in Andover - Tested First, Written Price Second

Fast, Reliable Duct Sealing Across Andover

Duct sealing in Andover typically runs $800 – $2,400 for a whole-house job depending on access, duct material, and whether we’re working in a 1990s Colonial Revival with standard flex-duct or a 1920s retrofit where the chimney flue became the return chase. Most Andover homeowners see the work completed in a single day, with written pricing agreed before we start and the 365-Day Done Right Promise backing every seal. Call (361) 326-5060 for a free estimate – we’ll walk your system and give you the exact number.

Call (361) 326-5060

We’ve worked in Andover homes long enough to know the difference between a Bancroft subdivision attic with torn vapor barriers and a Center Street center-chimney Colonial where the duct chase is literally 300-year-old brick. Our crews dispatch from the Boston office and serve Andover neighborhoods including Birds Hill, Shawsheen Heights, and the historic district around Central and School streets. That local knowledge matters because Andover’s housing spans four centuries of construction methods, and each era demands a different sealing approach. We don’t guess. We inspect, price in writing, and seal by the book.

Why Hollis Air Duct Cleaning Is Andover’s Preferred Duct Sealing Company

Hollis Air Duct Cleaning has been part of the Garrison Partners family since 2004, and our Duct Sealing team has built a reputation in Andover by showing up inside the quoted window, pricing before we touch anything, and leaving the site clean. Homeowners here aren’t looking for the lowest teaser quote – they’re looking for a crew that won’t turn a $900 job into a $2,800 surprise once the van is in the driveway.

Our technicians are background-checked, uniformed, and expected to perform under The Garrison Code: arrive squared away, explain what we’re doing in plain terms, and stand behind the work for a full year. The 365-Day Done Right Promise means if a seal fails, we come back at no charge – including a free second visit. That’s written down on every job, not mentioned verbally and forgotten.

Phones are answered by a live person 24 hours a day, 7 days a week. No voicemail loops, no callback queues, no waiting until Monday to schedule. Dispatch is coordinated from our Boston office, and crews serve Andover locally with the equipment and parts to finish most jobs in one visit.

HVAC Duct Sealing in Andover

HVAC Duct Sealing in Andover means closing the gaps, seams, and disconnected joints that let heated and cooled air escape before it reaches your rooms. In a town where January highs hover around 34°F and heating systems run hard for six months, leaky ducts in unconditioned attics or crawlspaces can waste 20 – 30% of the energy you’re paying for. We use professional-grade mastic, mesh reinforcement, and mechanical fasteners – not duct tape, which dries and fails – to create permanent seals that hold through Andover’s freeze-thaw cycles and humid summers.

A typical whole-house HVAC duct sealing job in Andover runs $800 – $1,800 for accessible systems in basements or conditioned spaces. Attic and crawlspace work, or homes with chimney-chase retrofits, range $1,200 – $2,400 due to access time and the hand-work required. We price by the system, not by the vent, and the number is written before we start.

Chimney-Chase Retrofits

Andover’s center-chimney Colonials present a unique challenge: the original flue was often repurposed as a duct chase during 20th-century forced-air conversions, creating tight, irregular runs that defeat standard rotary brushes and require hand-sealing with mastic and mesh before any sealing work can hold. We inspect these with cameras first, then brush and seal the liner seams by hand.

Flex-Duct in Unconditioned Spaces

The 1990s Colonial Revivals in Bancroft and off High Plain Road typically use flex-duct routed through hot attics and cold crawlspaces. We repair torn vapor barriers before sealing – summer humidity condenses on cold ducts and dissolves mastic within a season if the barrier is compromised.

Duct Repair in Andover

Duct Repair in Andover addresses the physical damage that makes sealing impossible: crushed flex-duct from storage boxes in attics, rusted metal ducts in damp basements, and disconnected joints where settling has pulled sections apart. We see this constantly in Andover’s 1960s-70s split-levels off Lowell Street, where the original galvanized ductwork has corroded at the seams after sixty years of humidity, and in historic homes where retrofitted ducts were forced through spaces never designed for them.

Duct repair in Andover typically costs $400 – $1,200 for section replacement or reconnection, and $1,000 – $2,400 when combined with full-system sealing. We use the same written-price protocol: inspect, document, quote, then work. No moving targets.

Corroded Metal Duct Replacement

Older galvanized steel ducts in Andover’s mid-century homes often rust through at the seams, especially in basement runs near the slab. We cut out damaged sections and replace with properly sized metal or insulated flex, sealed to the existing system with mechanical fasteners and mastic.

Disconnected Joint Reconnection

Settlement, vibration, and poor original installation pull duct joints apart over time. We reconnect with sheet-metal screws, draw bands, and two coats of mastic – not tape alone – so the joint stays sealed through heating season expansion and contraction.

Trusted Brands We Service in Andover

Our equipment roster includes Rotobrush rotary brush systems for agitation cleaning, Nikro negative-air machines for containment, and sealing and filtration products from Aprilaire, Abatement Technologies, and Guardsman. We stock common parts and materials locally, so Andover homeowners aren’t waiting on shipping for a vapor-barrier repair or a cabinet seal. When we quote a job, we confirm we have what we need to finish it – The Garrison Standard doesn’t permit half-completed work because a part didn’t arrive.

Common Duct Sealing Problems We See in Andover Homes

• Chimney-chase air leaks in center-chimney Colonials. The original flue liner in these 1700s homes was never meant to handle conditioned air, and gaps pull attic air directly into the return stream. We brush the chase, seal liner seams with mastic and mesh, and verify with pressure testing.
• Condensation-dissolved mastic in Bancroft attic flex-duct. Summer humidity hits 80°F+ attic air against 55°F supply ducts; without intact vapor barriers, moisture condenses and turns last year’s seal into sticky dust. We repair barriers first, then seal.
• Aerosol sealant failure in irregular post-and-beam chases. The 1700s framing around repurposed chimney voids creates pockets and bypasses that aerosol mist can’t reach. Hand-work with mastic and mesh is the only reliable method here.
• Shared dryer vent stack backpressure in Lowell Street apartments. Sealing a unit’s branch duct without checking the common lint pathway can push lint into neighboring units and create a fire hazard. We inspect the full stack before sealing any branch.

Pricing for Duct Sealing in Andover, MA

We Also Serve Cities Near Andover

Our crews regularly work in Andover and the surrounding communities – Lawrence, Wilmington, Lowell, and Reading. The same written pricing, background-checked technicians, and 365-Day Done Right Promise apply across the service area. Dispatch from our Boston office keeps response times predictable for scheduled duct sealing work throughout the region.

FAQs About Duct Sealing in Andover