House Bolt Strength and Mudsill Plates
Mudsill Plates were invented by Harlen Metal Products after the Northridge Earthquake to increase bolt strength and to reduce mudsill splitting caused by oversized holes, a phenomenon which is discussed below.
Thousands of homes had split mudsills for two reasons: the wood mudsill split because the bolt to mudsill connection was too weak to keep the wood mudsill from splitting, or the bolts were miss-installed with oversized holes. Most of the time it was because of oversized holes.
OVERSIZED BOLT HOLES