TinnerFlow
Dampers, Penetrations & Life Safety · Dampers & Life Safety

Duct through rated floor with firestop

Rated horizontal assembly

ConnectionSystem-specific duct joint
SupportIndependent supports

Before you start

  • Confirm floor rating, duct type, sleeve, annular space, support, firestop system number, backing, sealant depth, and access.
  • Verify the listed system matches the exact floor construction, duct material, shape, size, and opening.
  • Inspect the opening and keep it free of debris and incompatible materials.
  • Coordinate inspection before concealment.

Tools and materials

Exact listed firestop-system components, sleeve where required, backing material, sealant or mortar, independent supports, depth gauge, labels, manufacturer system sheet, and installation tools.

Lay it out

  1. Center the duct in the opening as required by the listed system.
  2. Mark backing depth and sealant depth.
  3. Keep support attachments separate from the firestop unless the system shows otherwise.

Set and support it

  1. Support the duct independently above and below the floor.
  2. Maintain the listed annular space.
  3. Prevent movement while the firestop cures.

Make the connection

  1. 1

    Verify the exact listed firestop system.

  2. 2

    Prepare and clean the opening.

  3. 3

    Install sleeve or backing exactly as shown.

  4. 4

    Place firestop material to the required depth and geometry.

  5. 5

    Tool and finish the surface as required.

  6. 6

    Label and document the system.

  7. 7

    Complete inspection before concealment or loading.

Check the install

  • The system matches the floor, duct, opening, and rating.
  • Backing and sealant depths are correct.
  • The annular space matches the listing.
  • The duct remains independently supported.
  • Documentation and labels are complete.

Common mistakes

  • Using a generic firestop product without a listed system.
  • Stuffing an oversized opening with scrap material.
  • Letting the duct move while the system cures.
  • Using the wrong backing depth.

Stop and ask

Stop if the listed firestop system cannot be identified or does not match the floor assembly, duct, opening, or annular space.