What must be removed from reusable lumber before it is stacked?

The correct answer is that nails must be removed from reusable lumber before it is stacked. This is crucial for several reasons. First, nails left in lumber can pose serious safety hazards. Workers handling the wood could sustain injuries from sharp protrusions, leading to cuts or puncture wounds. Furthermore, nails can damage other materials or equipment during transport or storage, leading to additional costs or safety concerns.

Proper preparation of lumber, including the removal of nails, also contributes to the integrity of the lumber itself. Nails can impact the structural stability of the stack and result in uneven surfaces or potential collapse when the lumber is stored or moved. Additionally, when lumber is reused, removing fasteners allows for easier inspection, treatment, or repurposing of the wood.

In contrast, while splinters, paint, and debris may also need attention when preparing lumber, they are generally not as critical as removing nails. Splinters can be managed through careful handling, paint can be addressed if it's hazardous, and debris can often be cleaned off without posing a significant risk. Therefore, ensuring that nails are removed is essential for maintaining safety and usability with reusable lumber.