Slide 13 of 45
- Undersized Washers
- Washers should always be used where the bolt head or nut bears directly on wood.
- Usually washers will be used on the post side that is opposite the hold-down.
- Square plate washers should be used instead of round malleable washers.
- This will help better prevent the bolt pulling through the end stud during an earthquake.
- The figure shows a round washer that has pulled through the hole. Note also that the hole was oversized to begin with.
- Substitution of Lag Bolt for Through Bolts
- When through bolts are specified, lag bolts should not be used. A lag bolt, even if it is the same diameter, will not have the same strength as a through bolt.