Step 4:

Inside Access
Where the sill plate is accessible on the inside, such as in an unfinished room or garage, the anchor bolts may simply be fitted from the inside of the house.
  • Using the bracket as a template, drill through the sill plate with a wood bit of appropriate size
  • Drill into the concrete below with a concrete bit using a hammer drill. It may be easier to drill a smaller pilot hole first
  • Remove any cement dust from the hole with a vacuum cleaner. Using a "blow" attachment or a compressed air wand is more effective at removing dust at the bottom of the hole.
  • Measure the depth of the hole with a probe to determine the bolt insertion depth.
  • If using epoxy, pour epoxy into the hole and coat the rod with more resin
  • Hammer the bolt into the hole until it is fully inserted. Fit a nut over the end of the bolt first to minimize burring of the bolt head, or to allow any burring to be removed by unthreading the nut.
  • Remove the nut, fit the bracket over the bolt, replace the nut and tighten with a wrench.
  • Bolt or nail the bracket to the stud. Drill pilot holes somewhat smaller than the nail or lag bolt diameter to minimize splitting of the wood.
The photo shows a commercial anchor bolt bracket designed for nailing
I highly recommend that anyone attempting to implement this type of retrofit consult with a local engineer before proceeding. Building code requirements will vary with your locality. The design of seismic and wind load resisting systems for residential construction is a fairly complicated topic. The proper design of anchor bolts embedded in concrete is also a complicated topic. <br><br>Some additional comments:<br><br>Step 3: Note that the plywood sheathing carries most of the lateral load, not the stud to bottom plate connection. Reinforcing the stud to bottom plate connection for shear is not really necessary.<br><br>Step 4: The type of bracket you show in the photo is designed to resist an uplift force, not a horizontal shear force. The manufacturer representatives with Simpson Strong Tie and/or USP can assist you in selecting appropriate connector products for a given application.<br><br>When using epoxy anchors, you want to use products that are tested and approved for this purpose. The major manufacturers of these products include Hilti, Simpson Strong Tie, Epcon, and Powers. Again, I recommend talking to the manufacturer's representatives to select appropriate products. The strength of adhesive anchors can vary greatly depending on the type of epoxy, anchor diameter, spacing between anchors, proximity of the anchor to the free edge of the concrete, depth of embedment, and strength of the concrete.<br><br>Step 9: When replacing the plywood sheathing, I would recommend installing 2x4 blocking behind the plywood between the studs. The blocking would be set with the wide face vertical. The existing sheathing above and new sheathing below can then be continuously nailed to the blocking. Size and spacing of nails should meet local code requirements.<br><br>Although you can buy those nailing plates at home centers, they are not load rated for retrofit applications. They are commonly used in factory built truss fabrication, but in this case they are installed under controlled conditions with special presses. Simpson Strong Tie and USP make load rated connectors for this type of application, but you will need to talk to them to select an appropriate product. <br><br>Step 10: The angle bracket shown is probably not a good choice for this application. Again, the manufacturer's reps should be consulted for appropriate product choice.
This is a great instructable for an experienced do-it-yourselfer! And it doesn't just apply to the West Coast -- as several recent news items remind us, there are epicontinental earthquakes which can affect the midwest and east coast as well.

About This Instructable


19 favorites


More by adaviel: Grey water re-use system Landing Craft for a Motorcycle Installing a Mini-Split Heat Pump
Add instructable to: