1
Measure the thickness of the wooden sill and the length of the wall with a measuring tape. Your local building code may specify how many J-bolts you need for a length of wall, but if not, choose a common distance such as every 3 feet. Divide the length of the wall by the spacing and add one, to figure how many J-bolts you need. If your sill is a 2-by-4, choose J bolts that are about 8 inches long. Otherwise, add an extra inch for each additional inch of sill thickness.
2
Pour the cement and level the surface.
3
Place the first J-bolt 1 3/4 inch in from the outer edge of the cement foundation and about 6 inches from the start of the wall. Push the curved end down into the cement until 2 1/2 inches show above the surface, if you're using a 2-by-4 sill. Otherwise, place the bolts half the width of the sill from the edge and let the straight end stick up the height of the sill plus 3/4 inch. Align the straight ends of the bolts so they're vertical, using a level.
4
Measure the correct spacing for the next J-bolt and place it the same way. Continue down the edge of the cement until you place the final bolt about 6 inches in from the other end.
5
Smooth the cement around the J bolts with a trowel and double-check that they're vertical and sticking up the correct amount. Wipe off any cement that happened to get on the visible part of the bolts with a damp rag. Wait for the cement to dry.
6
Lay the sill on the cement beside the J-bolts and mark beside each bolt on the sill with a pencil. Drill a hole at each mark in the center of the sill that's big enough for the J-bolts to go through.
7
Lay the sill atop the J-bolts with the holes aligned above the bolts and tap it down until it's resting against the cement. Screw the nuts on the J-bolts with a wrench to anchor the sill in place.
