Introduction: Trick for Attaching Sill Plates to Concrete Footings

About: I am an employee of Autodesk, Inc.

Attaching sill plates to continuous footings on the first try can be a challenge.

Traditionally, contractors will lay the sill plate on top of the anchors and bash it with a hammer to mark the location of the anchor bolts. Typically the board will move between hammer blows, and you never end up with a clean mark on the sill plate. Also, the anchor bolts will be slightly out of level, so only the tallest anchors make a mark.

This trick will help you precisely mark the location of anchor bolts in sill plates.

All you need (on top of the anchor bolts, washers and nuts) is two things:

  • chalk
  • some small sections of pipe (1/2 copper couplings fit perfectly over a standard 5/8" anchor bolt)

Step 1: Prepare the Tallest Anchors

Ok, so you'll need to balance the sill plate on the tallest anchors to start...

  • Measure them all with a tape measure and pick the two or three tallest ones.
  • Thread on a nut, and then put a square washer
  • Adjust the nut so that the washer makes a nice little platform to balance the sill plate
  • Rub some chalk onto the top of the anchor bolt

Step 2: Prepare the Short Anchors

So, the short anchors will need some special treatment to mark the board...

  • Thread a nut onto the anchor
  • Rub some chalk onto the rim of one of our pipe couplings
  • Put the coupling over the anchor so it rests on the nut with the chalk side facing up
  • The coupling should sit just below the top of the anchor bolt (for now)

Step 3: Align and Mark the Sill Plate

Now, we'll need to mark the underside of the sill plate...

  • Align the sill plate with the footing, balanced on top of the tall anchor platforms.
  • Adjust the nut on the short anchors so that the coupling comes into contact with underside of the sill plate
  • Hold the board in place and gently tap the board above each anchor with a hammer (becareful not to move the sill plate!)
  • With chalk, outline the square washers on the tall anchor bolts (just in case we didn't get a good mark from the tapping.)

You should now have some really nice marks where the anchor bolts need to be!D

Step 4: Drill, Baby, Drill!

Now just drill right on the marks we've made. ..

  • Over-drill the holes slightly. 11/16" bit for 5/8" anchors
  • You can now flip the sill plate over and with a hammer, bash it onto the anchors. (it should go without too much of a fight)
  • Tighten the nuts over the square washers

Your'e Done!

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