HVAC repair

✅ STEP-BY-STEP HVAC DUCT PATCHING GUIDE (BASIC + INSULATED DUCT)

1. Turn Off HVAC System

  • Shut down the system to avoid air pressure pushing through while you're working.
  • This also prevents dust or adhesive fumes from entering the living space.

2. Inspect and Clean the Damaged Area

  • Wipe down the duct using a dry cloth or mild degreaser.
  • Remove any rust, dust, or condensation using a wire brush or sanding pad.
  • Let it dry completely.

3. Cut and Remove Damaged Sections (If Needed)

  • If the hole or tear is too large, cut out the damaged portion with metal snips.
  • For small punctures or tears, you can patch directly over them.

4. Apply Aluminum Foil Tape

  • Use UL 181-rated aluminum foil tape for air ducts.
  • Seal over the damaged area or seams at least 1 inch beyond all edges.
  • Press firmly and smooth out wrinkles to ensure airtight adhesion.

5. Seal with Mastic Duct Sealer (for Long-Term Durability)

  • Using a brush or gloved hand, apply HVAC-grade mastic sealant over the taped area.
  • Cover all edges and overlapping tape.
  • Let it dry fully (typically 24 hours) before turning the system back on.

6. Re-Insulate the Duct (if previously insulated)

  • Wrap new R6 or R8 insulation around the patched area.
  • Use insulation tape or zip ties to secure.
  • If the original duct was flex duct, seal the outer vapor barrier as well.

7. Check for Leaks

  • After 24 hours, turn the system back on and inspect for any air leaks using:
    • Your hand (feel for airflow)
    • Incense/smoke test
    • Or a pressure test if available

✅ TOOLS & MATERIALS CHECKLIST

  • Aluminum Foil Tape (UL 181-rated) – Used to seal small cracks, tears, and seams on ductwork. Provides a strong, heat-resistant, airtight seal.
  • Mastic Duct Sealant (HVAC-grade) – A flexible, long-lasting paste applied over tape and joints to create a permanent air-tight seal. Ideal for irregular surfaces.
  • Wire Brush or Sanding Sponge – Cleans off rust, debris, or old adhesive to ensure proper bonding of sealant or tape.
  • Utility Knife or Metal Snips – Used to cut out damaged sections of metal ductwork or trim insulation as needed.
  • R6 or R8 Insulation Wrap (for insulated ducts) – Wraps around ductwork to maintain temperature efficiency and meet code requirements.
  • Insulation Tape or Zip Ties – Secure insulation wrap around the duct after patching. Helps maintain the integrity of the vapor barrier.
  • Clean Cloth or Degreaser Wipes – Used to remove dust, oil, or condensation before applying tape or sealant.
  • Gloves (nitrile or work gloves) – Protect your hands from sharp edges, mastic, and insulation fibers.
  • Safety Glasses or Goggles – Prevents debris, insulation, or mastic from getting into your eyes during cleaning or sealing.

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