Once the ledger is in place, you can use it to locate the footing, laying out the site and footing locations with batterboards and mason's lines. Mason's line can be stretched tightly without breaking and won't sag. Don't use a substitute. Batterboards must be rigid enough to stand straight against the tension of tightly pulled layout lines, so use stakes long enough to be driven securely into the ground.
There are 6 steps to completing this project:
Mark the center of the outside post location on the ledger. Partially drive a screw or nail at the bottom edge of the ledger at this mark to serve as a tie-off point for a plumb line. Drop a plumb line from the center mark. This transfers the point to the ground accurately.
Drive a batterboard near the wall at the bottom of the plumb line with the crosspiece level. If the ground slopes away from the house, install the crosspiece close to the ground so the batterboard at the opposite end will be no more than 3 feet high. Make a mark on the crosspiece aligned with the plumb line. Tie one end of the mason's line to a screw driver near the mark. Wrap the line several times around the crosspiece and line it up with the mark on the last wrap. Position the batterboard for the outside corner about 3 feet beyond the location of the footing.
You can either preassemble the batterboard or drive the batterboard stakes and attach the crosspiece. Attach the crosspiece with one screw if you haven't preassembled it. Wrap the line at the center of the crosspiece and stretch tight. Stretch the string until it is tight, level the line with a line level, and fasten the other end of the crosspiece with another screw. Install the remaining batterboards at the other corners.
Stretch the lines tightly, and adjust the batterboards until the lines just touch at their intersections. Square the corners using the 3-4-5 triangle method (see project tip). Once the corners are square, mark each crosspiece where the line crosses the top edge. This provides a reference point if the line gets moved inadvertently.
Mark the center of the corner footings by dropping a plumb bob from a tripod (a camera tripod will do nicely) so the plumb line just touches the intersection of the layout lines. Insert a landscape spike where the plumb bob comes to rest. Tie coloured tape or ribbon to the spike for visibility. Measure and mark the layout lines for the footing positions between the corners. Slip a small piece of tape over the line at the footing spacing.
Drop a plumb line at each piece of tape. Drive a landscape spike where the plumb bob comes to rest. Tie a piece of coloured tape or ribbon to each spike for visibility. If wind disturbs the plumb line, use a piece of plywood as a windscreen.
