Ladders are devices that workers use to step up or gain access to elevated surfaces.  There are many different types of ladders based on the application and materials used in their construction.

Types of Ladders

There are several basic types of ladders, including rope ladders and rigid ladders. Types of rigid ladders include:

• Step ladders - Step ladders are hinged and can be used at a fixed angle.
• Extension ladders - Extension ladders are divided into two or more lengths for convenient storage and transportation, and so that the ladder can be lengthened for use. A pulley system can allow the ladder can be easily extended by an operator on the ground.
• Telescoping ladders - Telescoping ladders are a hybrid between step ladders and extension ladders.
• Roof ladders - Roof ladders can grip the ridge of a pitched roof using a hook at the top of the ladder.
• Hook ladders - Hook ladders contain a hook at the top that can grip surfaces like windowsills.
• Rolling ladders - Mounted on wheels or casters so that workers can easily move the ladders into place.
• Marine ladders and dock ladders - Made from materials that can resist corrosion, such as stainless steel or anodized aluminum.

Construction Material

Ladders are commonly constructed with the following materials:

• Wood - Ladders made of wood are less expensive but heavier than ladders made of light-weight metal materials.
• Aluminum - Aluminum ladders weigh less but conduct electricity.
• Fiberglass - Fiberglass ladders are suitable for working near wires because they are good electrical insulators.

Specifications

Specifications to consider when selecting ladders include:

• Number of steps
• Depth of steps
• Climbing angle
• Slip resistance of the treads
• Storage - Some ladders contain a platform or tray for holding tools and materials.
• Duty rating - Ranges from Type 1AA (375 lbs.) for extra heavy-duty industrial use to Type 3 (200 lbs.) for light-duty commercial use.
• Attachments:
  • Standoff - An attachment at the top of a ladder to hold it away from the wall.
  • Stabilizer - An attachment at the top of a ladder that grips the wall and increases ladder stability.

Standards

ANSI A14.1 - Ladders - Wood Safety Requirements

ANSI A14.2 - Ladders - Portable Metal - Safety Requirements

ANSI A14.3 - Ladders - Fixed - Safety Requirements

ANSI A14.5 - American National Standard for Ladders - Portable Reinforced Plastic - Safety Requirements

Image credit:

Terra Universal, Inc.