Can Flexible Ductwork Go Down Ceiling Joists?

Between Ceiling Joists

• Ceiling joists are the beams that provide structure and stability for your primary ceiling area, between your main floors and your attic or upper crawlspace. Drywall is installed underneath the joists, and insulation is installed between the joists. You can run flexible ductwork between joists as well, as long as you dodge the insulation. This is one of the primary benefits for this type of ductwork, as long as you avoid problems that can occur in tight spaces.

Angles

• Flexible ductwork usually carries air and exhaust that is heavily laden with moisture. It is very easy to move flexible ductwork at strange angles to fit between tight joists or move the ductwork down to an area that will work better for remodeling. But the more twists and turns that the ductwork takes, the more easily condensation will be able to build and create pooling water and leaking problems. Keep angles to a minimum, and always at a decline.

Air Flow

• Air flow is also an important consideration. Never install flexible ductwork between ceiling joists where it becomes cramped or bends in on itself. This will cause a reduction in necessary air flow for your system. The result will be decreased efficiency and potential problems with condensation. Never squeeze ductwork into an area.

Ductwork Outlets

• When you install flexible ductwork between your ceiling joists, have a proper exit strategy. Venting out of soffits or the sides of walls is acceptable. Venting out of rooftops can also be done, but this can create more potential for leaks. You can also vent out close to your foundation if your need to drop ductwork into your basement.