Step 2 – Select the Proper Height
To ensure you choose the ladder best suited to your needs, follow the Werner height safety chart shown below. Extension ladders should be 7 to 10 feet longer than the highest support or contact point, which may be the wall or roof line. This will allow enough length for proper setup, overlap of ladder sections, height restrictions of the highest standing level, and where appropriate, the extension of the ladder above the roof line. The highest standing level is four rungs down from the top.
The highest permitted standing level on a stepladder is two steps down from the top. A person standing higher may lose their balance and fall. A person's maximum safe reaching height is approximately 4' higher than the height of the ladder. For example, a typical person can safely reach an 8' ceiling on a 4' ladder.
Step 3 – Select Performance (Duty Rating)
Ladders are designed and constructed to safely hold up to a specific amount of weight. Most ladders come in five different Duty Ratings identified by their grade and type. The Duty Rating is defined as the maximum safe load capacity of the ladder. A persons fully clothed weight plus the weight of any tools and materials that are carried onto the ladder must be less than the duty rating.
Ladders are also built to handle the demands of various applications. For example, a ladder used frequently on a construction site by rugged workers should typically be stronger and have a corresponding higher Duty Rating than a ladder used by a lighter person for light chores around the home.
Workers should be advised to consider both the weight which will be on the ladder and the work application and to select the proper grade of ladder which is designed to handle anticipated usage.
The terminology of Ladder Grades, Duty Ratings, and Types may initially be confusing. Remember that the Duty Rating is the maximum safe load capacity of the ladder. Hence, Duty Ratings are described in terms of pounds, such as a 300 lb. Duty-Rated Type IA ladder which is designed for extra heavy duty professional use where the total weight on the ladder does not exceed 300 pounds.
Step 4 – Select the Right Material
The final step in selecting the right ladder is the choice of the proper material. Grainger offers ladders made from fiberglass and aluminum. Each material has characteristics which make it best for certain applications, or one material may simply fit the personal preferences of the user. For example, potential contact with electrical wires, or a hostile environment such as exposure to certain chemicals or outdoor storage, should have a major impact on the material selection.