A door installation cart is an engineering control that may help reduce heavy lifting and carrying while installing doors.  It consists of a wheeled platform to transport and position doors.

DoorJak 50 and DoorJak 100 

These models allow a single individual to safely and effortlessly transport and install doors. The DoorJak 50 (figure 1) supports doors weighing up to 250 pounds, making it ideal for standard residential and light commercial doors. The DoorJak 100 (figure 2) is built to handle doors up to 750 pounds, accommodating heavy-duty commercial and industrial doors. Both models operate on a similar principle: the cart is placed in an upright position, the door is lifted onto the platform, and then, through a crank adjustment, the platform is tilted to a reclined position. A safety strap secures the door during transportation to the installation site, where it is then aligned with the doorframe using the cart's adjustable height setting. This process not only simplifies installation but also ensures the door is installed accurately and securely.

To load a door, the door installation cart, such as the DoorJak, is placed in its upright position and the door is lifted on to the platform (figure 3). Then, with a crank adjustment the platform is tilted into a reclined position, then a safety strap used to hold the door in place. Next, the door is wheeled to the installation site. The door is be wheeled up to the doorframe, tilted upright and then wheeled into place for installation. The DoorJak has an adjustable height setting so that the door can be lined up flush with the hinges. Once installation is complete the strap is simply removed and the DoorJak is lowered out from under the door.  The DoorJak can also be used for door removal.

Hardnox LLC offers two models that allow a single person to safely and easily transport and install doors. The Doorjak 50 (figure 2) can support doors up to 250 lb while the Doorjak 100 (figure 3) can support doors up to 750 lb.

Figure 1. Hardnox LLC Doorjak 50 (Photo courtesy of HARDNOX LLC)

Figure 2. Hardnox LLC Door Jak 100 (Photo courtesy of HARDNOX LLC)

Figure 3. A door installation cart lifting a door during installation (Photo courtesy of HARDNOX LLC)

DOOR STUD^® PRO SERIES and DOOR STUD^® HEAVY 

The Door Stud^® is another door installation tool cart designed for portability, offering solutions for both pre-hung and slab doors. It comes in two models: the PRO SERIES (figure 4), with a capacity of 300 pounds, and the HEAVY (figure 5), capable of handling doors up to 500 pounds. These tools facilitate single-person, hands-free installation, and the installer by stabilizing the door during the installation process. 

Figure 4. The Door Stud^® PRO SERIES (Photo courtesy of Home Innovation Holding)

Figure 5. The Door Stud^® PRO SERIES (Photo courtesy of Home Innovation Holding)

A door installation cart may increase productivity by making transport of doors faster and door installation more efficient.

Some lifting may be required to place the door onto the door dolly. Other materials (plywood, drywall, granite) can be moved using a Door Jak.  

Dan Anton, PT, PhD, ATC; and Kaya Mills, SPT – Eastern Washington University

• Residential Construction
  • Install doors, windows, attic access and associated hardware
    • Lifting and Carrying (Manual materials Handling)