For maximum stability, extension ladders should be pitched at a 75.5 degree angle. One way to check the angle is to stand with your toes against the bottom of the ladder and your arms extended straight out. If you can grasp a rung at shoulder height, you’re in the ballpark.
Another way to determine the angle is to use the Ladder Safety app from the National Institute for Occupational Safety and Health (NIOSH). Just hold your mobile device against a side rail and the app displays the angle while using visual and audio cues to guide you. A red indicator tells you the ladder pitch is too steep or shallow; a green indicator accompanied by a steady tone means you’re within 2 degrees of 75.5 and are good to go.
The app also features a guide ?to choosing, inspecting, accessorizing, and using ladders. Accessibility features include a high-contrast mode that you can activate at the touch of an icon. Ladder Safety is free and is compatible with iOS and Android devices. Download it from iTunes or at the NIOSH website. —Bruce Greenlaw is a contributing editor to JLC.