Replacing Flex Ductwork in Houston Attics: Signs, Code and What to Expect

Most Houston homes move every bit of cooled air through flexible ductwork in the attic. Flex duct is quick to install and easy to route, which is why builders use it. It is also the part of your system that takes the worst of the Houston climate: summer attic heat, Gulf humidity, and years of people stepping on it to reach abox of decorations. When it fails, your system works harder to deliver lessair, and you pay for that every month.

Here is how totell when your ductwork needs replacing, what a proper replacement includes,and what drives the cost. Beede AC & Heating has worked in Katy and Houstonattics since 2010.

Why flex duct wears out faster in Houston attics

Heat. On a July afternoon a Houston attic canpass 130°F. Years of that bakes the outer jacket brittle until it cracks andtears.

Humidity. When the insulation is thin or torn, cold supply air meets humid attic air and the duct sweats. The water soaks the insulation, drips onto the drywall and takes out what is left of the insulation value.

Sagging. Flex has to be strapped and supported along its length. Without enough support it sags, and every sag chokes airflow.

Crushing. Storage boxes, cable installs and past repairs flatten runs. A run crushed to half its size moves far less than half its air.

Age. Older flex was built to lower insulation values than current code. Even without damage, it loses more cooling to the attic than new duct.

7 signs your Houston home needs newductwork

•    Rooms that nevercool down. The room at the end of the longest run is usually thefirst to suffer. See [link: Why some rooms are hotter than others].

•    Power bills thatrise with no change in how you use the system.

•    A torn or crackedouter jacket you can see from the attic hatch.

•    Sweating ductsor water stains on ceilings under a duct run.

•    Kinked, crushedor sagging runs lying across the attic.

•    Weak airflowat 1 or more registers while others blow hard.

•    Disconnectedruns. A run that has pulled loose at a boot or the plenum cools yourattic instead of your home. We find these more often than you would think.

Repair or replace?

A single crushed run or 1 disconnected boot is a repair: reattach it, seal it, strap it. When the problems are spread across the attic, when the outer jacket is brittle everywhere or the insulation is soaked, patching 1 run at a time costs moreover 2 summers than replacing the system of ducts once. Your tech will tell you which one you have and show you photos from your attic.

What a full duct replacement includes

•    Sizing every runfor the airflow that room needs, not copying what was there before.

•    R-8 insulatedduct. Current energy code calls for R-8 insulation on ducts in an attic. Much of the older flex in homes built before current code is rated lower.

•    Sealedconnections with mastic at every joint, collar and boot.

•    Proper support,strapped so runs stay straight, open and off sharp edges.

•    New plenums,boots and collars where the old ones are rusted, crushed or leaking.

•    Haul-offof the old duct.

•    An airflow checkat every register before we leave.

What duct replacement costs in Houston

4 things set the price: how many systems the home has, how many supply and return runs eachsystem feeds, how easy the attic is to work in, and whether the plenums and boots need replacing too. A 1-story home with 1 system and an easy attic sits at the low end. A 2-story home with 2 systems and a tight attic takes more labor.

We price it flat and in writing before any work starts. Financing available.

Replace ducts with your AC, or separately?

If your AC orfurnace is near the end of its life, do the ducts at the same time. The atticis already open, the crew is already there, and the new system gets matched toductwork that can carry its airflow. A new high-efficiency system on old,leaking, undersized duct never delivers the efficiency on the label. See AC installation and replacement.

If your systemis newer and the ducts are the problem, replacing the ducts alone is the rightcall.

Duct replacement questions we get inHouston

Do you need a permit toreplace ductwork in Houston?

Inside the Cityof Houston and in most surrounding cities, yes. Duct replacement is mechanicalwork and needs a permit. We pull it.

How long does it take?

Most 1-2 system homes take 1 day.

Will new ducts fix a hot room?

Often, when thecause is a crushed, leaking or undersized run. If the room is hot because ofafternoon sun or missing attic insulation, we will tell you that too.

Can you replace only the bad runs?

Yes, if therest of the system is in good shape. That is a repair, and we will quote itthat way.

Book a duct inspection

A Beede tech will go into your attic, photograph what is there and give you a written price. Call 281-222-9591 orbook online. We serve Katy, Cypress, Richmond, Sugar Land, The Woodlands and the rest of Greater Houston.

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