Your foundation serves as the structural base on which your home rests. Whether you have a basement or just a crawl space, the upper portion or your house must fasten in a secure way to the foundation beneath. You can accomplish this with anchor bolts that extend from the interior of the concrete wall, up and through the sill plate, which serves as the connection point between the concrete and your home’s structure. You will install the bolts before the concrete hardens, a process called “wet setting.”
Refer to local building code about the minimum spacing of anchor bolts. Standard spacing is 3-feet apart, but in areas where earthquakes are common, spacing may be closer. Purchase anchor bolts and have them ready for installation before you pour the foundation walls.
Pour the walls and smooth the top of the concrete with a hand trowel. The top need not be perfectly level in order to insert the anchor bolts.
Push the angled end of an anchor bolt vertically into the wet concrete. The anchor bolt has a straight threaded end with a bend on the other end. The bend goes into the concrete and the threaded end remains out of the concrete.
Leave approximately 1 1/5 inches of the anchor bolt above the level of the concrete. Repeat with each anchor bolt, centering each one in the middle of the concrete, halfway between the sidewall forms.
Insert the anchor bolts quickly to reduce the risk of the concrete hardening before you get them all in.
Tamp the wet concrete around the top of each bolt with a small hand trowel to settle it securely around each bolt and allow the concrete to harden.
Things You Will Need
- Hand trowel
- Wet concrete walls
- Anchor bolts
- Wear long-sleeves, long pants, gloves and protective eyewear when working with wet concrete.
- Place plastic rebar caps on top of the exposed anchor bolts until you install the sill plate. Falling on a protruding anchor bolt may cause an injury.