Duty ratings were setup to provide some consistency and standards governing the safe construction, design, testing, care and use of portable ladders of various types and styles.
Ladder styles include portable stepladders, step stools, extension ladders, trestle ladders, sectional ladders, combination ladders, single ladders, platform ladders, and articulating ladders.
Each duty rating relates to a correlating maximum weight capacity (or load capacity) the ladder can safely carry. The maximum weight or load is the combination of several factors:
Safety standards require a Duty Rating sticker to be placed on the side of every ladder. There is no correlation between the ladder length and weight capacity. So do not assume that a ladder with longer reach has a higher weight capacity.
There are five categories of ladder Duty Ratings:
Type l
A Type I ladder is the most widely used for professional services like that of contractors, public utilities, and construction workers. Regardless of the material construction of the ladder, Type 1 ladders are built in lengths from 3 to 20 feet. This rating is broken down into three subcategories:
Type II
Type 11 ladders also run in lengths of 3 to 20 feet long. They are used in more commercial applications like painters, interior decorators, maintenance workers, and electricians. They have a weight maximum of 225 lbs. Type II ladders are manufactured in wood, fiberglass, and aluminum and are commonly used for medium-duty use.
Type III
Type III ladders are most typically household ladders. They only handle a load capacity of 200 lbs and are primarily used for light-duty use. These ladders are typically manufactured in lengths between 3 to 6 feet.
Here is a quick recap of duty ratings and load capacities:
Type III (Light Duty) | 200 pounds |
Type II (Medium Duty) | 225 pounds |
Type l (Heavy Duty) | 250 pounds |
Type lA (Extra Heavy Duty) | 300 pounds |
Type lAA (Extra Heavy Duty) | 375 pounds |