Snap-Lock Branch Duct · Straight Runs & Assembly

Snap-lock pipe concealed above hard ceiling

Inaccessible branch

ConnectionSlip joints with sealant
SupportBand/strap per approved spacing

Before you start

  • Confirm hard-ceiling limits, access panels, damper locations, inspection requirements, and final branch route.
  • Verify every joint, hanger, damper handle, and terminal can be finished before concealment.
  • Stage labels, camera, fasteners, sealant, hangers, and access equipment.
  • Do not rely on future access unless an approved panel is shown.

Tools and materials

Snap-lock pipe and fittings, approved fasteners, sealant, complete hanger material, damper labels, camera, inspection light, and hand tools.

Lay it out

  1. Place joints and dampers where they can be reached before closure.
  2. Coordinate access panels for service items.
  3. Mark the concealed branch route and critical components.

Set and support it

  1. Install every permanent support before closure.
  2. Keep the branch independent of ceiling framing and drywall.
  3. Maintain service clearance around dampers and joints.

Make the connection

  1. 1

    Complete and inspect every longitudinal snap lock.

  2. 2

    Seat, fasten, and seal every slip joint.

  3. 3

    Install permanent hangers and check for sag.

  4. 4

    Operate every damper and verify access.

  5. 5

    Remove loose screws, scraps, and debris.

  6. 6

    Photograph concealed joints, supports, dampers, and terminal connections.

  7. 7

    Complete the pre-cover inspection before ceiling closure.

Check the install

  • Every joint is seated, fastened, and sealed.
  • All supports are complete and independent of the ceiling.
  • Required service items remain accessible.
  • No loose debris remains.
  • Photos document concealed conditions.

Common mistakes

  • Closing over an unfinished hidden-side joint.
  • Burying a damper with no access.
  • Leaving pipe temporarily wired or resting on ceiling framing.
  • Failing to document concealed work.

Stop and ask

Stop ceiling closure if any joint, support, damper, label, access requirement, or terminal connection cannot be inspected and verified.