Air Duct Replacement in Kansas City, MO

When does duct replacement beat duct repair?

Most Kansas City homes do not need everything torn out. The honest answer depends on what the duct is made of. Galvanized trunk-and-branch in a basement is usually worth keeping. That steel outlives the furnace it feeds. What fails is the sealing at crimped round takeoffs, where old cloth duct tape dried out and let go. That is a sealing job, not a replacement job. Fiberglass ductboard plenums are the opposite case. Once the inner face has microbial growth or the board is soft at a corner, cleaning it only erodes it further. Those come out and get rebuilt in sheet metal.

Attic flex is the other common replacement. Sagging between joists, kinks at the turns, a torn vapor jacket with condensation underneath, rodent damage near rim joist penetrations. Flex that has been crushed by stored boxes will not recover shape. We replace the run and support it properly instead of re-hanging damaged duct.

Panned joist returns and stud-cavity returns raise a different question. They pull lint from basement laundry and dust from finished-basement work directly into the air stream. Lining or ducting those is often the bigger comfort improvement.

A 1950s ranch with whistling registers usually has an undersized return, not bad supply duct. Replacing supply runs there changes nothing. Ask any contractor to measure static pressure before agreeing to a full replacement.