Protect your loved ones and your investment in the New Madrid Zone
St. Louis sits near one of the most active seismic zones in North America. Our historic brick homes are beautiful, but vulnerable. Learn how to secure your home today.
Why St Louis, MO?
The New Madrid Seismic Zone (NMSZ) produced the strongest earthquakes in recorded US history between 1811 and 1812. Geologists estimate a 7-10% chance of a repeat event (M7.5+) in the next 50 years.
Unlike California, where the ground is broken and dissipates energy, the bedrock in the Midwest is solid. Seismic waves travel further and hit harder, making older St. Louis masonry especially vulnerable to collapse.
St. Louis’s older masonry homes — many built before modern seismic codes — are particularly at risk. Unlike wood-frame construction that can flex under seismic stress, unreinforced brick and stone walls are brittle and can crumble rapidly. A targeted seismic retrofit can dramatically reduce the risk of collapse and protect your family and investment.
Key Retrofitting Projects
We offer flexible options, which you can adapt to the different needs of each project.
Anchor Bolting
Securing the sill plate to the foundation
- Drill through the mudsill into the concrete foundation at code-required intervals
- Install expansion anchor bolts to create a rigid connection between wood framing and foundation
- Add oversized plate washers and nuts to distribute load and prevent pull-through
- Seal all penetrations with appropriate caulk to prevent moisture intrusion
Cripple Wall Bracing
Stiffening the short wood-framed wall above the foundation
- Apply structural plywood sheathing to the face of cripple wall studs to resist lateral forces
- Install blocking between studs to ensure proper load transfer from floor to foundation
- Fasten sheathing with structural nails at code-specified spacing along edges and field
Automatic Gas Shut-off
Preventing gas leaks and fire after a seismic event
- Install a seismic gas shut-off valve on the main gas supply line to automatically stop flow during strong shaking
- Strap water heater to wall studs using approved flexible connectors to prevent tip-over
- Secure other gas appliances to resist lateral movement and protect flexible gas lines