If you’ve ever wandered the charming streets of Philadelphia, you’ve probably noticed the distinctive star bolts on Philadelphia houses. These iconic features are more than decorative. they serve an essential structural purpose and hold a fascinating place in the city’s architectural history. But what exactly are star bolts, why are they necessary, and how are they installed? Let’s explore their story and why they remain a treasured element of Philadelphia’s historic row homes.
Figure 1
History and Significance of Star Bolts
Star bolts trace their origins back to colonial times when brick masonry and timber were the primary building materials. In Philadelphia, row homes became a staple of residential construction. These homes featured sturdy brick walls and wood-framed floors and roofs, with wood joists spanning side to side and anchoring into pockets within the masonry walls.
However, while these wooden joists reinforced the interior “party” walls, the front and back masonry walls needed additional bracing to prevent them from bowing or buckling under pressure. Builders of the time developed a clever solution: long iron anchors, or tie rods, that extended through the masonry walls and secured to the joists.
As time passed, these iron anchors began to deteriorate, especially when exposed to wet and dry cycles in the exterior masonry walls. Without sufficient bracing, walls could bow or even collapse. To solve this, builders began retrofitting these walls with external anchors. These anchors were functional and featured visually appealing washers, often in the shape of stars—thus the name “star bolts.”
Why Are Star Bolts Needed for Philadelphia Row Homes?
The need for star bolts on Philadelphia houses stems from the aging construction materials in many historic row homes. Over decades, masonry walls may begin to bow outward, creating structural risks. In many cases, stabilizing the wall with star bolts is a more cost-effective solution than rebuilding it entirely.
The repair involves installing tie rods that secure the masonry walls to the building’s floor joists. The visible star-shaped washer on the exterior provides aesthetic charm and functionality, distributing pressure evenly across the wall to ensure stability.
Star bolts are particularly common in Philadelphia, where preserving historic architecture is a priority. They maintain the structural integrity of these homes and retain their historical character.
How Are Star Bolts Installed?
Installing star bolts on Philadelphia houses is a precise process that requires a skilled contractor
1.Assessment and Planning:
Consult a structural engineer to assess the extent of the wall’s bowing or bulging and determine the appropriate placement and number of star bolts required. Also, obtain necessary permits from local authorities, as structural modifications often require approval.
2. Preparation:
Clearing interior areas where bolts will penetrate may involve removing drywall or rerouting electrical and mechanical systems.
Erect scaffolding to safely access the exterior wall sections where the star bolts will be installed.
3. Drilling Pilot Holes:
Mark precise locations on the exterior wall for each star bolt installation.
Drill pilot holes through the exterior brick wall at the indicated locations using a rotary hammer drill with a suitable masonry bit.
Figure 2
4. Drilling Through Joists:
From the interior, continue drilling through the floor or ceiling joists aligned with the exterior pilot holes. This ensures the tie rods will pass through and anchor securely.
Figure 3
5. Installing Tie Rods:
Insert threaded steel tie rods through the drilled holes, extending from the exterior wall into the interior and passing through the joists.
Figure 4
On the interior side, place washers and nuts onto the tie rods and tighten them to secure the rods against the joists.
6. Attaching Star Plates:
On the exterior, place the star-shaped plates (also known as star washers) onto the protruding ends of the tie rods.
Fasten the star plates by tightening nuts onto the tie rods, ensuring they are flush against the brick surface.
Figure 5
7. Tightening and Adjustment:
Gradually tighten the interior and exterior nuts to apply even tension, drawing the exterior wall closer to the building’s framework and correcting any bowing.
Continuously monitor the wall’s alignment during tightening to avoid overcorrection or damage.
8. Finishing:
Apply appropriate sealant around the tie rods where they penetrate the exterior wall to prevent water infiltration.
Repair any interior finishes disrupted during installation, such as replacing drywall or repainting.
How Much Does It Cost to Install Star Bolts?
The cost of installing star bolts varies depending on several factors, including the severity of the wall’s damage, the size of the building, and the materials used. On average, homeowners can expect to spend between $1,000 and $1,500 per anchor.
The total cost can increase for row homes requiring multiple anchors, but it remains a more affordable alternative to completely rebuilding a masonry wall. Additionally, installing star bolts typically causes minimal disruption to the building’s interior or exterior, preserving its historic character.
Star Bolts on Philadelphia Houses: Matrix Construction Real-Life Experience
At Matrix Construction, we’ve worked on numerous projects involving the installation of star bolts on Philadelphia houses. In a notable case, we were contracted to renovate the facade of a historic three-story row house. We noticed slight bowing in the masonry walls during the renovation and wanted to prevent further damage.
Our team assessed the structure and determined installing star bolts was the best solution. We used tie rods to anchor the walls to the interior joists and added star-shaped washers on the exterior. Not only did this restore the home’s structural integrity, but it also preserved its historic charm, much to the homeowner’s delight.
To learn more about this project, visit Innovative Facade Renovation for a Typical Philadelphia Row House.
What Makes Star Bolts Unique?
One of the most intriguing aspects of star bolts is their ability to combine form and function. Originally designed for structural reinforcement, their star-shaped design has become a celebrated decorative feature in Philadelphia’s architectural heritage.
Curious passersby often ask, “What are those star-shaped decorations on old homes?” Knowing their purpose adds a deeper appreciation for the city’s historic architecture. These bolts are a testament to the ingenuity of early builders, who found ways to marry practicality with beauty.
How Can Homeowners Maintain Star Bolts?
If you own a historic home in Philadelphia with star bolts, regular maintenance is essential for preserving its functionality and appearance. Here are some tips:
- Inspect for Rust: Metal components may corrode over time. Treating rust early can prevent further damage.
- Check Alignment: Ensure the bolts remain tight and aligned, as loose bolts may compromise the wall’s stability.
- Consult Professionals: If you notice significant bowing or damage, contact a contractor experienced in historic preservation.
Taking these steps can keep your home safe while honoring its historical character.
Conclusion
Next time you stroll through a historic neighborhood in Philadelphia, look closer at the star bolts on Philadelphia houses. Now you know these charming features are more than decorative—they are integral to the city’s architectural identity, blending functionality with timeless appeal.
If your home has bowing walls or you’re curious about adding star bolts as part of a restoration project, contact a professional contractor like Matrix Construction. We’re here to help preserve your home’s history and integrity while celebrating the beauty of Philadelphia’s past.
Ready to bring new life to your historic row home? Contact us today for a FREE Consultation!
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