Seismic Retrofitting: Earthquake Bracing for Your Home's Foundation
For homes built before modern seismic codes — especially those on a raised foundation — an earthquake can do more than crack drywall. It can shift the house right off its foundation. Seismic retrofitting reinforces the connection between your home and its foundation, and braces the crawl space walls beneath it, so your home has a fighting chance in a major earthquake. Foundation Solutions builds seismic retrofits as part of a complete foundation repair plan.
What Is Seismic Retrofitting?
Seismic retrofitting — also called earthquake bracing — adds engineered connections and reinforcement to an older home’s structure specifically to resist the sudden, lateral forces of an earthquake. Two components matter most:
Foundation Bolting
Anchors the wood sill plate to the concrete foundation so the house can’t slide off during ground movement.
Cripple Wall Bracing
Adds structural plywood panels to the short walls in a crawl space that separate the foundation from the main floor, so they don’t rack and collapse.
Homes built before the mid-1980s, particularly those with a raised perimeter foundation, are the most likely to need both.
Signs Your Home May Need Seismic Retrofitting
A retrofit is usually about prevention, not visible damage, but a few things are worth checking:
A free inspection is the most reliable way to know exactly where your home stands.
How We Retrofit Your Foundation
1. Foundation & Crawl Space Assessment
We evaluate your foundation type, cripple wall height, and existing connections to determine exactly what your home needs.
2. Foundation Bolting
Code-compliant bolts and reinforced washers anchor your home’s sill plate securely to the foundation.
3. Cripple Wall Bracing
Structural plywood panels are installed against the crawl space walls to keep them from racking or collapsing.
4. Holdown Hardware & Final Check
Holdown brackets are added at critical points, and our team verifies the retrofit meets current code.
Seismic Retrofitting vs. Settlement Repair
Seismic retrofitting and foundation settlement repair solve two different problems. A retrofit is built to resist the sudden, dynamic forces of an earthquake — it doesn’t correct a foundation that’s already sinking or shifting due to soil issues. If you’re also noticing signs of foundation settlement, such as cracks, sloping floors, or sticking doors and windows, that’s a separate repair addressed with foundation underpinning or house leveling. Many older homes benefit from both a settlement inspection and a seismic evaluation, and our team can assess both during the same visit.
Backed by a Warranty You Can Count On
Every seismic retrofit we install is backed by warranty-supported protection and engineered to current code requirements. If you have questions about your retrofit down the road, our team is here to help.
FAQs
About Seismic Retrofitting
Does My Home Need Both Foundation Bolting and Cripple Wall Bracing, or Just One?
It depends on your foundation type. Homes where the wood framing sits directly on a continuous foundation typically need bolting only. Homes with cripple walls in the crawl space need both bolting and bracing. Our team confirms which applies to your home during a free inspection.
Will Seismic Retrofitting Prevent All Earthquake Damage?
No retrofit can guarantee zero damage in a major earthquake, but a properly retrofitted home is significantly less likely to shift off its foundation or suffer a cripple wall collapse — two of the most common causes of serious earthquake damage to older homes.
Is Seismic Retrofitting Required by Code for Older Homes?
Requirements vary by city and county, and some areas require retrofitting for certain older home types at the time of sale or major renovation. Our team can tell you what applies in your area during your inspection.
Ready to Protect Your Home Before the Next Earthquake?
The best time to retrofit is before an earthquake happens, not after. Reach out and our local team will inspect your foundation and crawl space and recommend the right retrofit for your home.
Testimonials
I don't even know where to start with this review. From the first contact to the end of the job, Ryan and his crew were amazing - professional, knowledgeable, courteous, tidy and clean and very respectful of the impact the job had on me as the homeowner. The job was major, but I felt confident with the information that Ryan and his crew shared with me each step of the project. Since they are specialists, they are very busy so it took a while from start to finish but worth the wait! I could not be more pleased. They get an A+++ from me.
We had a consultation with a very knowledgeable engineer (Collin) who's extremely patient to answer questions and concerns we had. After a thorough walkthrough and measurements, it turned out the area which we thought might be problematic with leveling is only centralized and minuscule, not foundation-related. I'd like to thank Foundation Solutions for this engineer's detailed explanations, professional knowledge and recommendations. At the end, we acquired peace of mind and would highly recommend this company to anyone that may be seeking help with foundation related issues. If we are doing any addition/expansion of our house, we would definitely get in touch again for securing our foundation.
Kyle and the team are awesome! A corner of our foundation has a horizontal crack and when we go out for a quote, many companies explained how serious it is and give us a high estimation. Kyle came onsite and did a detailed inspection, explain why it crack, and how to properly fix it. Then few days later, gave us a reasonable estimate, and we decided to go with the service, they handled the permit, came to fix it in a day and did all the final inspection and passed, we have a smooth experience on the fix. My family are super happy with their service and already recommend to friends in case they need some work in the foundation.