How to Bolt a House to a Foundation

Older homes in hurricane or earthquake-prone areas might not be adequately secured to their foundation. In the event of high winds or shaking, the house could slide off its foundation. Normally, the lowest wood part of the house structure is the sill plate. The sill plate supports the wood structure of the house and rests on the concrete foundation. The sill plate is usually secured to the concrete with cast-in place bolts. This type of fastener is installed after the foundation has been poured but while the concrete is still wet. Additional bolts can be anchored into the concrete of existing homes by drilling holes through the sill plate and into the foundation.

Power drill
Drill bit set
Masonry drill bit
Hammer drill
Shop vacuum
Hammer
Socket set
Torque wrench

Instructions

- 1
  Go to the basement or crawl space of your house. Locate the wood sill plate that sits on top of the concrete foundation. That is the area where you will bolt your house to the foundation.
- 2
  Drill through the wood sill plate with a drill bit that is the same diameter as the concrete anchor to be used.
- 3
  Insert a masonry drill bit that is the same diameter as the concrete anchor to be used into a hammer drill. Place the bit into the hole in the sill until it comes into contact with the concrete underneath. Start the hammer drill and bore into the concrete to a depth that will accept the concrete anchor you will be using. Check the minimum depth of the hole required in the instructions that came with the anchor.
- 4
  Clean the drilled hole out with a shop vacuum.
- 5
  Place a washer onto the threaded end of the anchor. Twist the nut onto the anchor threads two turns. Insert the opposite end of the anchor into the drilled hole.
- 6
  Hit the nut on the anchor with a hammer to drive the anchor fully into the hole. Tighten the nut with a socket placed onto a torque wrench to the tightness specified in the anchor instructions.
- 7
  Install additional anchors in the same manner. Check with local regulations as to the spacing allowed between anchors.

Requirements for an Earthquake-Proof Structure

House Raising With Concrete Piers

Earthquake Damage