Air Duct Replacement in Houston, TX

What actually fails in a Houston attic duct system

Flex rarely fails along its length. It fails at the collar. A zip tie crushes the inner liner, the liner tears behind the tape, and cooled air feeds the attic. Cloth-backed duct tape is the other culprit. Attic heat cooks the adhesive and the tape curls off. Mastic does not do that. Old gray flex goes brittle and cracks when you move it.

Check some of this yourself. Pull a ceiling register and light up the boot. Black fuzz on the register frame means air leaks past it. Gray shadowing on ceiling paint says the same. Matted, dirty insulation beside a duct is filtered air. Feel around the filter grille for a draft.

Returns cause more grief than supplies. Postwar ranches in Oak Forest and Garden Oaks often pan a joist bay or use a stud cavity as the return path. Those cavities were never sealed. Heights bungalows on pier-and-beam hide their runs under the floor instead, where critters and standing moisture get at them.

Sometimes we say don't. A short-cycling oversized condenser is not a duct problem. Neither is a wet duct-board plenum. If the roof decking is coming off next spring, wait. Low-slope hip roofs with tight eaves make the far bedroom runs the hardest work in the house.