Flexible Ductwork — Installation & Replacement

Quiet, efficient airflow starts with properly built flexible ductwork. We design and install UL 181–listed, R-8 insulated flex to ACCA/SMACNA best practices: sized by Manual D, sealed airtight, fully supported, and routed on the shortest, smoothest path.

What “done right” means

• UL 181 flex with R-8 insulation in attics/crawls (R-6 only where code allows)
• Runs sized to target CFM and acceptable static pressure (Manual D)
• Inner core fully stretched, smooth sweeps, bend radius ≥ one duct diameter
• Airtight collars/boots: mastic + UL 181 tape; inner core clamped with listed draw bands; vapor jacket sealed separately
• Supports every ≤4 ft with ≥1.5″ straps; minimal sag; no kinks or crushed sections
• Metal trunks/plenums where appropriate, with flex “whips” cut to exact length for quiet, balanced supply and return

Installation process

1. On-site assessment — measure static pressure, map supply/return sizes, confirm routes and clearances.
2. Design & sizing — Manual D layout, trunk strategy, register/return selections.
3. Professional installation — cut to length, fully stretch and form arcs, seal cores and jackets, strap and insulate, label each run.
4. Test & balance — verify system static, confirm room CFM and temperature split; adjust dampers for even comfort.
5. Handoff — photo report, filter sizes, simple care intervals.

Why it matters

Correctly sized and sealed flex lowers energy use, reduces equipment strain, cuts noise, and delivers consistent temperatures to every room.

Schedule a technician for an on-site duct installation or replacement visit: 510-400-6425.

Keywords: flexible duct installation, UL 181 flex, R-8 insulated duct, Manual D sizing, HVAC duct replacement, duct sealing and balancing.