How to Mark the Anchor Bolts in a Sill Plate

Place one treated 2-by-8 flat on top of the foundation and against the outside of the anchor bolts. Although the anchor bolts may not be completely in line, your board should touch the outermost bolts that are in line.

Place the speed square so that it is aligned with one side of one anchor bolt. Make a mark with your pencil across the 2-by-8. Place the speed square on the opposite side of the anchor bolt and make another straight line. You should have two lines that are 1/4 to 1/2 inch apart, depending on the size of your anchor bolts.

Repeat this process down the length of the board. However, for anchor bolts that are too far away from the 2-by-8 to align with a speed square, use a framing square, which is much larger than a speed square and will reach farther.

Measure in from the outside of the foundation wall at each bolt. Transfer that measurement to each corresponding bolt mark on the 2-by-8 by measuring in from the outside edge of the 2-by-8 and in to the marks that were placed earlier. This will represent the center of the hole that must be drilled. Make this hole slightly larger than the anchor bolt to allow for some tolerance.

Drill all holes into the board where the marks intersect. If you have 1/4-inch bolts, use a 1/2-inch drill bit. If you have a 1/2-inch bolt, use a 5/8-inch drill bit. Once you have this board drilled, place it over the anchor bolts and tighten the nuts down. Place another 2-by-8 at the end of the previous board and repeat the process.