Extension ladders, which are also known as non-self supported ladders, are probably one of the most used and misused pieces of access equipment. They are a versatile tool with plenty of limitations and inherent dangers. This type of ladder should be used for short-term light work, for no more than 30 minutes. Choosing the right ladder and knowing how to use it is important. Research gathered by the Bureau of Labor Statistics show that falls are one of the top four causes of fatal occupational injuries from 1992 through 2009.
Purchasing the right types of ladders and maintaining them so that they comply with applicable standards is the responsibility of the employer. Employers are required by the Occupational Safety and Health Administration (OSHA) to provide training on the safe use of ladders as per OSHA 29 CFR§ 1926.1060. Safety inspections for ladders should be done on a regular basis to prevent injury. If a ladder is found to be damaged, it should be marked with a tag saying “Do Not Use”, and removed from service.
Choosing the Right Ladder
Extension ladders are made from wood, aluminum and fiberglass and come in various lengths. Choosing the right ladder for the job is very important. Because wood and metal are great conductors of electricity, it would be best to use a fiberglass ladder if you are doing electrical work.
Height Restrictions
Extension ladders range in length from 16 feet up to and exceeding 40 feet. All non-self supported ladders should extend a minimum distance of 3 feet past the edge they rest against but not more than 4 feet. As with any ladder, extension ladders should be at the proper height and angle for optimum safety and stability. When determining proper working height/angle, non-selfsupporting ladders should be set at a 4:1 ratio (see Figure 1) from the foot to the top support. Each section of a multi-section ladder must overlap the adjacent section by at least 3 feet for ladders up to 36 feet and 4 feet for 40 feet or longer extension ladders. For example, a 24-foot extension ladder will consist of two sections each 12 feet long, but the maximum extended length will be 21 feet, because the sections overlap by no less than 1½ feet when the ladder is at maximum extension.
