The Origin of Star Bolts

What are star bolts and why are they used?

You could be taking a stroll down any street in Philadelphia and you’re bound to spot a star bolt. Philadelphia is rich in colonial history, so it’s easy to assume these star bolts are decorative. While they look very charming in the way they align along the side of a brick house, they’re actually there to keep the front of the building intact.

Why are they needed? In older rowhouses, the strongest part are the joists, which run from side to side, and the front of the property is only attached at the very top and at the edges. Homes constructed before 1920 were built with lime mortar, which deteriorates over time due to weather exposure and causes the foundation at the front of the home to shift. Drilling parallel star bolts into the joists disperses the tension and keeps the structure stable.

The best part about star bolts? They keep our city’s rich architectural history alive.

If you have any questions about this topic or are thinking of buying, selling, or investing in real estate, give me a call or message me on our website.