Masonry Walls & Tie-Rods
Understanding building construction is integral for all firefighters however, knowing and identifying aspects of building construction and how it plays part in the buildings overall makeup is even more vital. Looking at a brick wall to some, is well just a brick wall. To others, looking at a brick wall is much more. So what is it? A brick wall or is this wall telling a story?
The brick wall to firefighters is in fact telling a story. In fact, these walls are known as masonry walls and in this case for our discussion, "load bearing" masonry walls. The construction of these walls began in the 1700s and ended around the mid-1900s. These walls built with stones, bricks, cement blocks or concrete blocks were designed to carry the weight that is transferred from the roof top to the buildings foundation.
Ever notice the stars or other subtle designs on masonry walls which are spaced strategically on the wall mainly in rows? These are commonly referred to as "reinforcing stars" or "anchor plates".
Here are some reasons for the use of this "décor" on masonry walls.
Building Stabilization. These were added to buildings during the late 19th century and early 20th century, these were used to connect and support tie rods in order to stabilize the building.
Visibility. Not all of these plates are visible from the street. Sometimes, these plates are hidden behind facades or not retrofitted to the walls leaving the exposed tie rods or cables nestled between the brick and mortar. In these instances, take note during pre plan and during the initial fire ground size up.
Fire Conditions and Collapse. These rods are known to fail under most fire conditions causing a collapse of the structure or parts of the structure.
Structural Integrity. Not all of these tie rods and plates were retrofitted as the building aged. In some instances, these tie rods and plates were installed during the construction of the building to give the building added integrity.
So a brick wall isn't just a brick wall, it has many components such as the 1 we just spoke about. Take time during your next pre plan and identify these plates on the structures should you have any in your jurisdiction. Understand and be comfortable with identifying key indicators in building construction. Keep in mind the role plates and tie rods play in possible building collapse should they fail under fire conditions. Remember a brick wall isn't just a brick wall, it's telling a story of what's behind it.
Until next time; work hard, stay safe & live inspired.