Which of the following should not be used to fasten the sprinkler system or building attachments?

Nails are typically not suitable for fastening sprinkler system or building attachments due to several important reasons. Nails do not provide the same level of strength and holding power as bolts, screws, or anchors, which are specifically designed to secure materials together more rigidly. In many applications, sprinkler systems are subject to vibrations and movement; nails can easily loosen over time due to these factors, compromising the integrity of the installation.

Furthermore, nails are not adjustable after installation. If alignment or positioning needs to be modified, nails cannot be easily removed or tightened, unlike screws and bolts that allow for adjustments. Additionally, nails may not be effective in securing heavier components or those that require a firm connection, unlike anchors that are specifically designed to expand within a material and provide a solid hold.

The preference for screws, bolts, or anchors lies in their ability to create strong, secure connections that can withstand the operational stresses and environmental conditions that a sprinkler system may encounter. Thus, using nails could lead to safety risks and operational issues within the sprinkler system.