Does Snap-Lock ductwork need to be sealed after installation?

After the ductwork is in place, you must seal the ductwork to prevent air leaks. We recommend using either clear silicone or HVAC tape to create a good seal at every joint. Wait until all of the ductwork is in place before sealing adjustable elbows. If using silicone, run a small bead at every joint, including along adjustable elbows, and smooth it over with your finger. If using tape, one wrap at every seam should be sufficent as long as the tape is applied well.

Additional information about Snap-Lock ductwork installation can be found here.