Air Duct Repair & Sealing in Herndon, VA
Your furnace can only heat the rooms its ducts reach. Leaky joints, crushed runs, and disconnected sections dump warm air into attics and crawl spaces. We find the leaks, seal them, and get your heat back where it belongs.
Signs Your Ductwork Is Losing Heat
Duct problems hide above ceilings and under floors. These symptoms give them away.
One room is always cold
A disconnected or crushed duct run starves the far rooms while the rest of the house overheats.
Dusty air right after cleaning
Leaky return ducts pull dusty attic or crawl-space air into your system.
Rattling or whistling vents
Loose joints and gaps make noise as air escapes through them.
Higher bills, same thermostat
When heated air leaks out, the furnace runs longer to hit the same temperature.
Visible damage in the attic
Torn insulation, hanging sections, or taped joints that gave up years ago.
Weak airflow at some vents
If some registers barely blow, the duct feeding them is usually the problem.
How We Find and Seal Duct Leaks
Sealing works only if you find every leak first. So we start by looking, not by caulking.
Walk the system
We trace your duct runs through the attic, crawl space, and basement, checking every joint and connection.
Show you the leaks
You see what we see: disconnected sections, crushed flex runs, failed tape.
Seal and repair
Joints get sealed with mastic and mesh. Damaged sections get repaired or re-hung properly.
Test the airflow
We check register airflow after sealing, so the improvement is real, not assumed.
Duct Repair Questions
What homeowners ask about their ductwork.
How do I know if my ducts are leaking?
Uneven room temperatures, weak airflow at some vents, and dusty supply air are the classic signs. We inspect the full run. Most leaks hide in attics and crawl spaces you would never look in.
Is duct tape good enough for sealing ducts?
Despite the name, standard duct tape dries out and fails on ductwork. We use mastic sealant and mesh tape rated for the job. They last.
Do you replace ductwork or just seal it?
We seal and repair. If a section is crushed, disconnected, or falling apart, we repair or re-hang it. Full replacement is rarely needed when the layout is sound.
Will sealing my ducts change my heating bills?
When heated air stops leaking into the attic, the furnace runs less to keep you warm. Less air lost means less fuel burned. The math is straightforward.
Can leaky ducts make the air dirtier?
Yes. Leaks on the return side pull in dust, insulation fibers, and crawl-space air. Sealing them keeps your indoor air to what is actually in your home.
How long does duct sealing last?
A professional seal with mastic or metal tape holds for many years — it isn’t something that needs redoing every season. We check your ducts during future tune-ups and touch up any spots that worked loose from vibration or attic heat.
Can you seal ducts hidden in a finished basement ceiling?
Yes, in most cases. We work through access panels and cut small openings only where needed, then close them back up. If your ductwork is fully enclosed, we’ll show you exactly where we’d need access before any work starts.
Every room should feel the heat.
Leaky ducts steal comfort and fuel all winter. Call now and we will track down the leaks.