Discover: Star Elements Serve Structural Purpose

Have you ever noticed a metal star on the side of an older brick building?  Have you wondered why it was there? There is a very practical reason for the ornament, other than for decoration.  

Bricks are held together with mortar, also known as masonry.  The weaker composition of old mortar can cause brick walls to bow, giving the wall a pregnant look.  To solve the problem, tie rods (or more recently, post-tensioned cables) are inserted and run through the building, from one side to the other.  A decorative metal piece called a pattress or anchor plate is placed on the outside wall and acts like a washer.  The rod or cable and the anchor plate are a load distributing combination.  When the outside nut located on the anchor plate is tightened, it pulls the bowed wall back into place.
 
In Minnesota, it is most common to see stars or a decorative “S,” but other shapes such as an “X” and a cross are observed.

—Wendy Petersen Biorn
Executive Director, Carver County Historical Society