Best Tools for Cutting Ductwork

Ductwork in the walls.

For most, home repair and homeownership go hand in hand. A leaky faucet, squeaky door, or busted window pane lead many homeowners into the exciting world of home repair. While most DIY enthusiasts leave HVAC repairs to the professionals, sometimes a situation arises where they might take on the challenge. It could be a new HVAC run for a playroom in the basement or replacing a section of damaged or deteriorating duct in the attic. Most folks learn early on that having the right tools for the job increases their chances for a successful repair.

Common HVAC Duct Materials

There are several types of materials used for HVAC ducts such as sheet metal, fiberglass board, and flexible duct. Having the correct tool for cutting the applicable material simplifies the process and provides a superior result.

Sheet Metal

Ductwork made of sheet metal.

The most common tool used to cut sheet metal is tin snips. The color-coded handles represent the type of cut the snips make. Tin snips with yellow colored handles are used for cutting straight lines and wide, sweeping curves. Tin snips with green colored handles cut straight lines and tighter curves to the right. Tin snips with red colored handles can also cut straight lines and tighter curves to the left.

There are many other tools and methods used to cut sheet metal ducts including hole cutters, roto zips, hole saws, and even jigsaws. Keep in mind that the cut edges of sheet metal are very sharp. A good pair of leather work gloves may spare you from a significant injury.

Fiberglass Duct Board

Fiberglass duct board is a sheet of insulated fiberglass with a thin foil layer affixed to one side.

V-groove tools are used to cut a V-shaped groove in the duct board. This allows the board to be folded into a 90-degree bend. By cutting several V-grooves into the board, it can be folded into a four-sided rectangular box which is a common component of an HVAC duct system.

The end cut off tool, also referred to as the staple flap tool, is used to finish off the edge of a cut board. Duct knives are versatile tools used in a variety of duct building circumstances. Hole cutting tools allow the user to cut precise holes in fiberglass duct boards.

Flexible Ducts

Ductwork in a ceiling.

Flexible HVAC ducts are comprised of a wire coil surrounded by a thin but durable plastic that is enclosed in a layer of fiberglass for insulation.

Wire cutters or tin snips are used to cut the wire coil in a flexible duct. A utility or duct knife is appropriate for cutting through the thin plastic and fiberglass insulation that surrounds the flexible duct. Tensioning tools are used to install and tighten nylon ties for fastening flexible ducts to metal duct collars.

These are just a few of the common tools used to cut HVAC ducts. There are many more available designed for specific duct cutting tasks. As with any home improvement project, safety should always be at the forefront. Wear protective gear such as respirators, safety goggles, and protective clothing before starting your project.