Mudsill Plates

Mudsill Plate to Increase Foundation Bolt Strength and Reduce Splltting

MUDSILL PLATES INCREASE BOLT STRENGTH AND HELP PREVENT SPLITTING OF THE MUDSILL

Mudsill Plates were invented by Harlen Metal Products after the Northridge Earthquake to increase bolt strength and splitting of mudsills caused by oversized holes, which is a universal code violation.    This is further discussed in this trade magazine article.

Foundation Bolts can be Strengthened with the Hardware

A bolt with a common round washer resists 840 pounds of earthquake force, put an MSP Mud Sill Plate) on top and it resists 1335 pounds, put it on the bottom and it resists 1665 pounds, and on the top and bottom 2040 pounds.  A 143% increase.

 

FOUNDATION BOLT EARTHQUAKE RESISTANCE COMPROMISED BY OVER-SIZED HOLE

Foundation bolt failure after the Northridge Earthquake from Over-Sized Holes

THIS MUDSILL SPLIT IN THE NORTHRIDGE  EARTHQUAKE AND IS THE REASON THIS SPECIAL WASHER WAS DEVELOPED.   

 

Here are some tests Harlen did on oversized holes

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Split Mudsill

SOFT WOOD MUDSILL WILL FAIL BEFORE MUCH HARDER CONCRETE AND BOLT. ESPECIALLY IF IT HAS OVERSIZED BOLT HOLES