Duct repair and sealing for New Orleans attics and crawl spaces
A good system connected to leaky ducts cools the attic instead of the house. We find disconnected runs, crushed flex and open joints, then repair and seal them properly with mastic.
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Leaky ductwork in a New Orleans attic can lose a large share of the cold air before it reaches a room, and the hot, humid attic air pulled in through return leaks makes the system work harder. Repair and sealing means reconnecting and supporting runs, replacing crushed flex and sealing every joint with mastic, usually in one day.
Where duct leaks come from
Updated September 2026
Most duct problems we find are simple and unglamorous: a run that slipped off its collar, flex duct crushed by someone walking the attic, joints held with cloth tape that let go years ago, or a return that pulls attic air through gaps around the filter box.
They matter more here than in cooler places. A supply leak dumps cold air into a sweltering attic, and a return leak pulls that hot, humid air straight into the system.
What decides the cost of duct repair and sealing
Duct work is priced on what we find in the attic or crawl space, not from a chart.
Extent of leaks
A few joints versus sealing the whole system.
Damaged sections
Crushed or torn flex replaced by the foot.
Access
Low attics and tight crawl spaces take longer.
Insulation
Wrap replacement on ducts where insulation has failed.
Return side
Rebuilding a leaky return or filter box adds work.
Testing
Pressure readings before and after to confirm the result.
What is included in a duct repair and sealing job
- Static pressure test before and after
- Inspection of every accessible run
- Disconnected runs reattached
- Crushed flex sections replaced
- Joints sealed with mastic and mesh
- Return and filter box sealed
- Photos of findings and repairs
Leaky Duct Joints
Every connection in a duct system is a potential leak: the plenum, each takeoff, each collar and each boot at the ceiling. Tape fails in attic heat, and gaps open as the house settles. We find leaks by sight, by feel and by pressure readings, then seal the joints with mastic and fiberglass mesh, which stays sealed in heat where tape does not. Sealing the return side is especially important, because that is where humid attic air gets pulled in.
Crushed Flex Duct
Flexible duct is easy to install and easy to damage. Crushed sections, sharp bends and runs sagging between supports all choke airflow, and the room at the end of that run never cools. We replace damaged sections, reroute runs with long gentle bends, and support them properly so they do not sag. Sometimes one crushed run is the entire reason a bedroom is uncomfortable, and fixing it takes an hour. We check that before anyone talks about a bigger system or a new duct layout.
Mastic Sealing
Mastic is a thick paste brushed over joints and seams, often reinforced with mesh tape. Unlike cloth duct tape, it bonds to the metal and flex liner, stays flexible, and does not dry out and peel in attic heat. It is the standard for a durable seal. We seal plenums, takeoffs and boots where we can reach them, and we are honest about sections that are too far gone to seal and need replacing instead. Sealing a duct whose insulation has already failed saves little and hides a problem.
Attic ducts, crawl-space ducts
Slab homes built after 1960 in Lakeview and New Orleans East run their ducts overhead through the attic, so every leak there spills cold air into the hottest space in the house. Older raised houses, including many around Algiers Point, sit on piers with crawl spaces instead of basements, and ducts run below the floor where damp air and the occasional critter take their toll. We inspect both kinds before recommending repair or replacement.
What a homeowner can fix and what needs us
| Task | Homeowner | Technician |
|---|---|---|
| Change the filter | Yes | |
| Reattach a boot you can reach | With foil tape | Mastic seal |
| Seal the whole system | Hard in attic heat | Yes |
| Replace crushed flex | Possible | Proper support and routing |
| Measure static pressure | No | Yes |
How a duct repair job runs
- 1
Airflow and pressure check
Static pressure and room airflow measured first.
- 2
Attic or crawl inspection
Every run, joint and support looked at.
- 3
Findings and quote
Photos of the problems and a written plan.
- 4
Repair
Reconnect, reroute and replace damaged runs.
- 5
Seal
Mastic and mesh on joints, plenums, takeoffs and boots.
- 6
Recheck
Pressure and airflow measured again.
Signs your ducts are leaking or damaged
- One or two rooms that never cool
- Dust building up quickly around vents
- Hot or musty attic smell from the vents
- Cooling bills rising with no other cause
- Whistling or rattling in the ceiling
- Weak airflow at far rooms
- Visible disconnected or sagging runs in the attic
Questions about Ductwork Repair & Sealing in New Orleans
Rooms that never cool, dusty vents, a hot attic smell from the vents and high bills are common signs. A pressure test confirms it.
No. Cloth duct tape fails in attic heat. Mastic or foil tape rated for ducts is the standard.
Usually one day for a typical attic system, longer for extensive repairs.
It can, because conditioned air stops escaping into the attic. The savings depend on how leaky the system was.
If most runs are sound, repair and sealing. If insulation has failed throughout or the layout is wrong, replacement.
Often a crushed or disconnected run to that room. We check that run first.
Yes. Sealing return leaks stops humid attic air from being pulled into the system.
Yes, including raised homes with ducts below the floor.
More ductless & ductwork we handle in New Orleans
Ductwork Replacement & New Duct Installation
Full duct replacement, adding supply runs and more.
Our ductwork replacement & new duct installation serviceMini-Split Deep Cleaning
Blower wheel cleaning, coil wash and more.
Mini-Split Deep Cleaning in New OrleansRooms that never cool?
Call and we will check the ducts before anyone suggests a bigger system.
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