What is an important maintenance practice for a stepladder?

Protecting a stepladder from corrosive materials is essential for its maintenance because these substances can cause degradation of the ladder's materials, particularly if it's made of metal. Corrosion can weaken the structure, leading to potential failures during use. By keeping the ladder away from corrosive environments, you extend its lifespan and ensure that it remains safe to use.

The other options present practices that can compromise the safety and integrity of the stepladder. Making the ladder heavy does not contribute to its maintenance and might hinder mobility. Using the ladder in wet conditions can lead to slips and increased risk of accidents. Storing it under heavy objects could also cause physical damage, potentially bending or misaligning the ladder structure, making it unsafe for future use.