Fast, Reliable Duct Repair & Sealing Across Lanham
Duct repair and sealing in Lanham typically runs $280-$680 for most homes, with same-day service available when you call before noon. We’re Bellows Air Duct & Vent Co., and we’ve been driving to Lanham since 1984 - long enough to know the difference between a 1965 Cape Cod off Annapolis Road and a 1978 split-level near Good Luck Road, and what each means for the ductwork hidden behind the walls.
Our technicians are background-checked, uniformed, and carry the equipment to handle most jobs in a single visit. We answer calls with a live person, 24 hours a day, and we’ll be there when we say. If your ducts are leaking, your upstairs is stuffy, or you’ve noticed a damp smell after heavy spring rains, call us at (844) 685-6342 for a free estimate.
Why Bellows Air Duct & Vent Co. Is Lanham’s Preferred Duct Repair & Sealing Company
We’ve worked in Lanham long enough to recognize the original spiral-lock galvanized duct trunks that builders in Prince George’s County installed during the 1955-1975 suburban boom. These aren’t standard systems. They’re hand-fabricated to fit tight crawl spaces, with irregular seams that off-the-shelf mastic connections often fail to seal. That local knowledge matters when a technician crawls under your rambler and knows what to look for before a single tool is lifted.
Our Duct Repair & Sealing in Lanham work is backed by our 90-Day Done Right Promise - in writing, no arguing. If it’s not right, we return at no charge. No paperwork required. We also camera-inspect every duct system before and after work begins, so you see what we see. Pricing is disclosed upfront, consistent with our founding promise of no scare tactics and no bait coupons.
Calls are answered by a live person, 24/7 - not a voicemail, not an app. Most jobs are completed in a single visit. And we offer a standing $50 off any repair over $250, plus a permanent 5% senior and veteran discount.
Our Duct Repair & Sealing Services in Lanham
Duct Sealing
Sealing in Lanham means dealing with decades of humidity cycling that has degraded original joints and connections. We use professional-grade mastic sealant applied with proper prep - not duct tape, which fails within months in our climate. A typical duct sealing job in Lanham runs $280-$450 for a single-system home. We seal trunk lines, branch connections, and register boots, then verify with camera inspection.
Flex Duct Repair
Many Lanham homes have had partial flex-duct retrofits over the years, often connected to original metal trunks with collars that weren’t properly supported. The sharp edges of hand-fabricated sheet-metal branches in these older homes cut through flex duct collars, creating hidden leaks behind soffit panels. We replace damaged flex runs with properly sized, insulated sections and secure them to prevent future abrasion. Flex duct repair in Lanham typically costs $180-$340 per run.
Metal Duct Repair
Original galvanized steel ducts in Lanham’s 1960s-70s housing stock corrode from the inside out where condensation pools in low spots. We patch or replace damaged sections, re-fabricate connections where original seams have failed, and reinforce structural supports that have rusted through. Metal duct repair in Lanham runs $320-$580 depending on accessibility and extent of damage.
Duct Insulation
Unconditioned crawl spaces and attic soffits in Lanham’s ramblers and Cape Cods expose ductwork to extreme temperature swings. We re-insulate with foil-faced rigid wrap or formaldehyde-free fiberglass, properly sealed at all joints. This prevents the re-condensation that destroys new mastic work. Duct insulation in Lanham typically costs $450-$890 for a full trunk-line wrap.
Mastic Sealant
Mastic is our standard for sealing in Lanham - not tape, not aerosol. We apply water-based, UL-181-rated mastic to all joints and seams, with proper cure time before system restart. On original galvanized trunks with irregular hand-fabricated seams, we often need to build up multiple thin coats rather than a single thick application that would sag or crack. Mastic sealant work is typically bundled with full sealing services.
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 Lanham
We carry professional-grade equipment and materials from Nikro, Honeywell, and Aprilaire - the same brands serious HVAC contractors specify for their own jobs. For Lanham’s older housing stock, we stock a range of mastic compounds, foil-faced insulation wraps, and custom-fabricated transition fittings sized for the non-standard dimensions common in 1960s-70s construction. This means faster turnaround and fewer return trips. We don’t substitute cheaper materials to hit a price point, and we show you what we’re using before we start.
Common Duct Repair & Sealing Problems We See in Lanham Homes
- Delaminated fiberglass duct liner. The original fiberglass liner used heavily in 1960s-70s construction degrades when humidity cycles expand and contract the adhesive. During routine cleaning, we regularly find gray, crumbly liner that has detached inside trunks - a problem that sealing alone won’t fix, since new mastic won’t adhere to failing substrate.
- Undersized trunk lines creating negative pressure. Many split-levels in the 20706 ZIP were built with trunk lines too small for the conditioned volume. The resulting negative pressure sucks crawlspace moisture into seams, breaking mastic adhesion within a season or two.
- Hand-fabricated branches cutting flex duct collars. Sharp edges on original sheet-metal branches - common in the tight soffit runs of Lanham ramblers - slice through retrofit flex duct connections, creating leaks that blow conditioned air into wall cavities.
- Condensation damage from humidity cycling. Lanham’s position in the low-elevation, inland portion of Prince George’s County produces some of the highest summertime relative humidity readings in the DC metro - regularly exceeding 80% RH. This drives condensation inside ducts served by systems that cycle on and off, accelerating mold growth and corroding metal from the inside.
Pricing for Duct Repair & Sealing in Lanham, MD
We’re transparent about pricing because we’ve seen what bait-and-switch looks like, and we don’t operate that way. Here’s what duct repair and sealing costs in Lanham’s market:
| Service | Typical Range in Lanham |
|---|---|
| Duct sealing (single system) | $280-$450 |
| Flex duct repair (per run) | $180-$340 |
| Metal duct repair | $320-$580 |
| Duct insulation (trunk line) | $450-$890 |
| Fiberglass liner replacement | $520-$940 |
| Emergency leak repair | $240-$420 |
Factors that affect your specific cost: accessibility (crawl space height, soffit removal), extent of liner damage, whether original metal needs fabrication versus standard replacement, and how many branch connections require sealing. We disclose the full price before work begins - the number on the phone is the number on the invoice. Estimates are free. Call (844) 685-6342 to schedule.
Standing offers: $50 off any repair over $250, free second opinion on any written estimate, $89 seasonal tune-up, and permanent 5% senior and veteran discount.
We Also Serve Cities Near Lanham
Our Duct Repair & Sealing team covers Bowie, Goddard, Lanham-Seabrook, and New Carrollton with the same response standards and upfront pricing. If you’re in Prince George’s County and your home was built during the 1955-1985 suburban expansion, we likely know your duct configuration before we arrive.
Serving Lanham, MD - Our Local Coverage Area
We’re based in the Lanham 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 Lanham
Because duct tape fails in Lanham’s humidity, and your original galvanized trunks have irregular hand-fabricated seams that tape can’t conform to. The mastic we apply is rated for wet locations and built up in thin coats that flex with metal expansion. Call (844) 685-6342 for a free inspection - we’ll show you the camera footage of where tape has failed.
No. Sealing over failing liner is a temporary fix that fails within months as more liner detaches. We remove and replace degraded liner with new, properly adhered material before sealing. This is the most common hidden issue we find in Lanham’s 1960s-70s stock. The full repair runs $520-$940 depending on trunk length.
Yes, if the smell is coming from moist air being pulled into leaky return ducts. Sealing prevents negative pressure from drawing crawlspace air into the system. We also check that your trunk line insulation is intact - saturated insulation holds odor and re-contaminates the air. Call (844) 685-6342 for an evaluation.
Split-levels in Lanham often have undersized trunk lines serving the upper level, creating low airflow and negative pressure that pulls in unconditioned air. We measure static pressure and airflow at each register, then seal leaks and may recommend trunk-line modification. Most split-level duct issues in Lanham trace to original design constraints, not equipment failure.
Standard duct sealing and insulation typically do not require a permit in Prince George’s County. If we’re replacing substantial metal ductwork or modifying trunk-line sizing, we handle permit research and any required filings as part of the job. We’ll tell you before work begins if your specific scope requires county notification.
Schedule Your Free Duct Inspection in Lanham
On Mistletoe Drive off Good Luck Road, we opened an original 1968 ramp-up junction in a crawlspace and found the fiberglass duct liner had detached inside the main trunk, blowing loose fibers into the bedrooms. We mastic-sealed 22 joints and re-insulated the whole trunk with foil-faced rigid wrap to prevent re-condensation. The homeowner had lived there fourteen years and never known.
That’s the work we do in Lanham. We crawl the spaces, we camera the lines, and we fix what we find - one honest price shown before we start, backed in writing for 90 days. No bait coupons. No price changes at the door. Calls answered by a live person, 24 hours a day.
Call (844) 685-6342 for your free estimate. We’ll be there when we say.
Written by Ray Castillo, Owner at Bellows Air Duct & Vent Co., serving Lanham since 1984.