Slide 43 of 45
Notes:
- Lag screws require pre-drilling
- When installing side plates, follow the manufacturer’s installation instructions carefully.
- Some do not need predrilling.
- Unless otherwise approved, lag screws require pre-drilling during seismic loading.
- Lag screws require pre-drilling even if you intend to use a pneumatic wrench.
- Be careful not to overtighten the lag screw during installation.
- This will “strip” out the hole.
- Never drive the lag screws with a hammer.
- Figure shows a photo of an anchor side plate being installed
- Lag screws require two different diameter pre-drill holes
- Lag screws require two different diameter pre-drill holes.
- If you don’t do this you may split the sill plate.
- If the sill plate is old lumber, it may crack upon installation
- New lumber will crack later, after drying
- This is a common construction error.
- Why do you need two different diameters?
- The larger diameter pre-drill hole is for the solid shank portion of the screw. This hole should be drilled the same diameter as the screw itself.
- The second hole is the pre-drill hole for the threaded portion. This hole must be smaller than the threaded diameter in order for the lag screw to grip the wood.
- Required pre-drill hole sizes for both lag screws and nails are shown in the Appendix.
