Two ladders and a plank create a stable work platform that requires less time to build and move than a traditional scaffold. Ladder jacks clip on two rungs of each ladder and hold a standard width scaffold plank. For optimal safety, the ladders are set at a common angle and set at a distance 24 inches less than the length of the scaffold plank. To increase safety, follow Occupational Safety and Health Administration (OSHA) guidelines and tie off to the structure nearest the ladder when your feet are higher than six feet from the ground.
Set up two extension ladders with the outside legs of the ladders set at the length of the scaffold plank minus 24 inches.
Install the ladder jacks. Walk up the ladder to the height you require a platform. Place the top arm of the ladder jack over one rang of the first ladder with the plank arm facing away from the building. Lower the ladder jack until the lower leg sits on a second ladder rang. Install the second ladder jack at the same height on the second extension ladder.
Set and centre the scaffold plank across the arms of the two ladder jacks.
An improper extension ladder climbing angle is a common cause of severe injury and death in construction. To determine the proper angle, set an extension ladder against the building. Place the tips of your shoes against the feet of the ladder. Hold your arms straight in front of you with your finger tips extended. Point your extended finger tips at the ladder rang nearest eye-level. Adjust the ladder until your finger tips touch or just rest on the top of the ladder rang, setting the ladder at the correct climbing angle. Employ a helper to aid with the installation of the ladder jacks and scaffold plank.