What is the maximum spacing of anchor bolts for a two-story house?

What is the maximum spacing of anchor bolts for a two-story house?

• A. 4 feet on center
• B. 6 feet on center
• C. 2 feet on center
• D. 8 feet on center

Answer: (C)

Anchor bolts are the hold-down that ties the sill plate to the concrete foundation, and their spacing determines how well wind and seismic forces are transferred from the top of the wall down into the foundation. In a two-story house, these forces are larger and the load path is longer, so bolts must be placed more frequently to keep the sill firmly secured along the entire wall line. Keeping the maximum spacing at 2 feet on center ensures there’s a fastener near each stud and at regular intervals, reducing the chances of uplift or wall separation during extreme loading. Spacing much wider would leave significant portions of the sill plate inadequately restrained, which isn’t acceptable for a two-story structure.

Anchor bolts are the hold-down that ties the sill plate to the concrete foundation, and their spacing determines how well wind and seismic forces are transferred from the top of the wall down into the foundation. In a two-story house, these forces are larger and the load path is longer, so bolts must be placed more frequently to keep the sill firmly secured along the entire wall line. Keeping the maximum spacing at 2 feet on center ensures there’s a fastener near each stud and at regular intervals, reducing the chances of uplift or wall separation during extreme loading. Spacing much wider would leave significant portions of the sill plate inadequately restrained, which isn’t acceptable for a two-story structure.